by Tom Gaylord
Writing as B.B. Pelletier
Webley Mark VI service revolver with battlefield finish. This one is rifled and shoots pellets.
This report covers:
- History and new together
- The firearm
- Field strip
- Differences between firearm and pellet gun
- Disassembly of the pellet gun
- Loading the pellet gun
- The rear sight
- Summary
History and new together
This is Monday when I usually write an historical report about an airgun or something. Well this is about the pellet revolver called the Webley Mark VI with battlefield finish, which is a modern air pistol, but today’s report will also be historical. Remember — I own both the pellet gun and the firearm it is patterned after.
Normally Part 2 is the velocity report. Today, though, we will be looking at some things we don’t usually get to see in an airgun report. Let’s begin with one of the big ones — field stripping the revolver.
The firearm
The Webley Mark VI revolver was made for the military in World War I, which was 1914 to 1918. At that time it was considered essential for a military weapon to be two things. The first is rugged. It had to stand up to all sorts of abuse that might range from tropical heat and moisture, through desert sand and heat, arid mud and dirt and even polar cold. It isn’t easy for a firearm to tolerate all those environmental extremes and still function reliably. Guns like the P-08 Luger that were made at the same time were made from machined parts with tolerances so tight that they kept out a lot of the bad stuff, while guns like the M1911 were made purposely loose to function even when they were dirty. Both approaches work, though the guns with tight tolerances do tend to start failing when they get wet or dirty, and especially both. So you design holsters that keep them clean even in hostile environments.
The Luger holster surrounded the pistol, keeping dirt out to the extent possible.
The design of the Luger with its tight tolerances makes it susceptible to any dirt that gets inside.
The M1911 pistol was made with loose tolerances to tolerate dirt better than guns like the Luger.
Semiautomatic pistols were a pretty new technology in WW1, but revolvers had been around for many more years. Revolvers also have tight tolerances. In many cases, and certainly in a double action revolver like the Mark VI, they are much tighter than the parts in a semiautomatic pistol, but for wartime use they also had to be designed loose to handle the dirt. That’s hard to do with a revolver, whose chambers in the revolving cylinder have to align precisely with the breech of the barrel so the bullet isn’t shaved off on one side when it jumps the gap from cylinder to barrel. A semiautomatic has a barrel that the cartridge is loaded into, so misalignment at this point isn’t an issue.
Webley locks up the loose cylinder in the Mark VI by lifting the bolt and rocking it forward when the trigger is pulled. This jams the cylinder into a semi-locked state at the moment of firing. The rest of the time it rocks side to side loosely and feels sloppy.
The Webley bolt (arrow) rocks up and forward a few hundredths of an inch to lock the cylinder in alignment with the rear of the barrel.
The pellet gun uses the same technique for locking the cylinder and indeed locks up even tighter than the firearm. Of course it isn’t more than a century old, either!
Field strip
The other thing a military sidearm must do is disassemble easily and quickly for cleaning and repair. It must not have any parts that can easily become broken or lost. The P08 Luger gets an F rating in this category, as it is not easy to disassemble. In its day the score would probably have been a C or better, because that was the state of the technology at the time. The 1911, in contrast, was rated an A back in its day and still gets a C today. Most double action revolvers were Fs for disassembly and haven’t improved much in the intervening century.
The Webley Mark VI, in sharp contrast to other revolvers, rates a A for ease of disassembly and cleaning, and a B for small parts loss, because one screw has to be removed from the gun. If you have a pocket or pouch to hold it while you clean — no problem.
Disassemble the gun any further and you are going where the designers never intended you to go. But for cleaning this is as far as you need to go because the barrel is already broken open for access.
Differences between firearm and pellet gun
The disassembly is one place where small differences between firearm and pellet gun show up. Once the disassembly screw is removed from the firearm the owner rotates the cylinder cam lever counter-clockwise (or anti-clockwise, as the Brits say it) and presses it against the cylinder cam that is spring-loaded. When the cam is moved slightly the cylinder becomes free and can be removed from the axis for cleaning.
Note the wide slot in the head of the firearm disassembly screw. It is slotted to accept a sixpence — which is one more item you’ll need in your kit if you want to remain true to form. If you want to be a yank, an American quarter or nickel works well.
The firearm disassembly screw was slotted to fit a common coin soldiers might have.
The old silver sixpence was 19mm in diameter — slightly smaller than an American nickel. An American quarter also fits the screw head nicely and gives you more to grab.
With the firearm disassembly screw removed, rotate the cylinder cam lever counter-clockwise until it pushes on the spring-loaded cylinder cam. Push the cam slightly and the cylinder lifts off the axis like this.
Disassembly of the pellet gun
The pellet gun disassembles in a very similar way, though the screw head no longer has a wide slot for a silver sixpence (that soldiers probably also don’t have). A screwdriver blade from a pocketknife works well. Once the screw is out the cylinder cam lever is rotated counter-clockwise and the cylinder is free to remove — the cylinder cam no longer has to be pressed.
The pellet gun disassembles in a similar way, though not exactly the same.
Loading the pellet gun
We know that the pellet cartridges are lifted up for extraction when the revolver’s barrel is broken open, but they don’t fall out unless the gun is tipped. If the barrel is broken all the way open, they fall down flush again. So, with them sitting down inside the cylinder, they make a perfect place for loading, because the pellets go into their bases.
With the cylinder exposing the cartridges this way, loading will be easy.
The rear sight
I was asked whether the rear sight is adjustable and I said it isn’t. But from the pictures it sure looks like it is. So let’s take a closer look at it and see for ourselves.
As you see, the pellet gun rear sight is one piece and not adjustable.
Summary
There are some things I wanted to cover about both the pellet gun and the firearm. This is a different report because we have the firearm to accompany the pellet gun. Most who buy the pellet gun will never own the firearm, and I wanted them to get a closer look at what their pellet pistol copies.
Very cool, I will have to get the ne of these.
It is a dead ringer for my newest pistol.
I stopped in to a local gun range Saturday, the had a Webley mkIV IN 38/200 in their used gun case. . It is marked “war finish” on the frame.
The only detriment is the flat spring that holds the cylinder stirrup closed is broken.
Because of that, I got it at a VERY good price.
Ian,
That is awesome! Is it a .455 or is it modified for .45 ACP?
It is in .38/200
a .38 caliber 200 gr bullet.
From what I under stand it’s close to the antique .38 S&W cartridge, but a heavier bullet.
So this air pistol is a copy of the MkIV since it uses a “38” caliber cartridge, not a .455 like the MKVI.
While at the shop I did a quick google search of the model, and for the price they were asking, i couldn’t pass it up.
45Bravo,
No, this revolver is a copy of the Mark VI, even though, as you point out, the cartridges are very like .357 Magnums. There are small differences between the Mark IV and the Mark VI besides the calibers.
The Mark IV is a true .38 caliber, where the .38 Special is really less than .36 caliber (0.357).
B.B.
Ian,
The .38 was a quite common cartridge used before and after WW1. The Brits, like us, preferred a little more knockdown when it came to their war weapons. I can’t blame them. The pop guns they give them now…
BB,
As you said, most of us will never own one of these. Part of me would really like to, but I do not have a use for it. I would have to have it in the original .455, not the shaved down .45 ACP. Then I would have to feed it…
Now this thing would most likely be welcomed at RRHFWA should it show up on my doorstep, even if I am not much for CO2.
RR,
Mine is modified for .45 ACP. That’s why there is a full moon clip in the photo in Part 1.
B.B.
BB,
I know. Many here in the US are. I do not know this for a fact, but it is my understanding that the .45 ACP is more powerful than the .455 Webley and repeated shooting can cause wear and damage to the Webley. Something to keep in mind.
RR,
I reload for it and according to a balistics program I have, the pressure of my reload is 8,000 psi. That’s less than the British load.
B.B.
B.B.,
Do you find that the .45 bullets you cast are a good match for your Webley’s .455 bore? If my memory serves, there is a slight difference in circumference.
Michael
Michael,
I don’t have a .455 bullet mold. Today’s .45 ACP molds are 0.451 or 0.452 and will not work. But there are proper molds available.
I will probably just buy bullets already cast and lubricated.
B.B.
B.B.,
Hunted Supply had relatively light weight cast lead bullets in .457 that might be sizable to say .455-6, probably some other casts available out their more local that you know of!
Good luck and have great fun getting her shooting at the range!
Shootski
BB,
That is probably a wise decision for many reasons. You do not want to put too much strain on the old gal. 😉
Back to The Show for a moment.
For those of you who are into the Beeman Chief, it will soon be available with 10 shot magazine and the QB78 will be available with synthetic stock.
Speaking of synthetic stock, TCFKAC will be bringing out the Benji 392/397 models with synthetic stocks.
Now back to your regularly scheduled program.
RR,
I was in the Beeman booth twice and saw the gun (repeater) but nobody would talk to me. So I passed it. I can always test one from Pyramyd AIR.
B.B.
BB,
That will be good. Over the years I have met a lot of diehard QB78 fans who will be very interested.
BB
Sixty years ago Ye Ol Hunter advertised Webley military pistols in Shotgun News for $24.95. Stupid me didn’t get one.
I very much enjoyed your report today and learned why my Luger holster is shaped the way it is.
Deck
Deck,
I have a Swiss Luger holster from 1918 and it’s shaped exactly the same.
B.B.
B.B.,
A bit off-topic, but this is a good place to ask.
With the lousy weather over the weekend I went into my warm basement and shot some of my CO2 replicas, including a couple of my Umarex Colts and my Tangfolio blowback 1911A1. Sometimes I wish a bit of blowback could be figured out in the design of the revolvers.
Looking at the classic revolver and classic auto-loader photos above put some questions into my head about actual firearms. Obviously the bolt of the P08 and the slide of the 1911 have an effect on the felt recoil of the gun. Does that effect slightly increase or decrease the felt recoil? Does that rearward force, a few milliseconds after the recoil produced by the gas expansion and bullet screaming out of the barrel, make a difference?
Furthermore, does that difference from revolvers, Webley-Fosberys excepted, make the felt recoil of a revolver different from that of an autoloader of comparable power? (The only handguns I’ve ever shot were air guns and toy guns.)
Michael
Michael,
The felt recoil for a revolver is much more sudden and therefore feels harder than for a semiautomatic in the same caliber. I find full-house .44 magnum rounds punishing in a revolver and pleasant in a Desert Eagle. Granted the DE is almost twice the weight of the revolver, but the recoil takes so much longer to transpire that it feels milder to me. Same in a rifle. A Springfield bolt action kicks the snot out of me, where a Garand is milder.
B.B.
B.B.,
I figured that might be the case. Thanks.
Michael
Michael
I always have wished that a manufacturer would make some type of blow back feel for Co2 revolvers. The conversation was brought up in the past with people commenting on different designs to accomplish it.
And just say’n. I’m thinking Umarex will probably be the one to do it. They seem to be leading the pack with air gun designs here lately. And I have said this in the past. They spit those new designs out pretty fast.
Now days it seems you think it and a manufacturer does it. Alot of cool stuff happening now days.
Gunfun1,
I agree completely.
I wonder who really deserves credit for the design innovations and production. It seems an awful lot of Taiwanese airsoft companies have been making excellent blowback, metal slide, green gas and CO2 pistols for some time. Many of the steel BB models now available originated as airsoft.
Michael
Michael
Yes that too. The air soft tech is there. Now only if they would make some that shoot pellets.
That’s the thing about airsoft. Alot of cool guns available. But I prefer pellet shooters over airsoft ammo or bb’s.
Maybe it will happen pretty soon. We’ll see.
Gunfun,
Just me, but if they were to design blowback in a revolver, I wish they’d delay the blow back just a bit, so the pellet/bb could exit the barrel before the muzzle would rise. Unlike firearms, the pellet/bb is not out of the barrel before recoil happens.
Doc
Doc
But remember. No matter if it’s a firearm or a pellet version. The shot is still affected by the recoil.
Even though that bullet leaves the barrel fast there has to be some effect on how the bullet leaves when the shot hits.
Maybe that’s why clamping a firearm changes results compared to how a clamped air gun does. Doesn’t it?
Maybe we need another test to verify the difference in a air gun and a firearm version.
I just want the recoil in a air gun version to simulate some sort of recoil. Heck maybe with the slower pellet it just might make you a better shot when you learn to, should I say control the shot.
I still say I like the recoil in a pellet pistol replica rather than no recoil. I want some recoil simulization when shooting than none at all.
Michael,
I wonder if squeeze cocking a HK P7 with the trigger back is a better way to fire double action than a traditional SA/DA revolver or semi auto because the strength of all the fingers are used to fire and control the pistol.
The reason I ask is its too expensive to go out and buy one to find out. I used to play with a Charter arms Bulldog in .44 as kid at my friends house. I wasnt strong enough the cycle the action with my finger, and the firing pin would put a hole in most anything in its way. The Webley looks very soldier proof to me tho.
Rob
Rob,
A cool design, the P7, but it was so inventive, it didn’t sell well. A discontinued gem.
Michael
You mention the tight lock-up on the cocked CO2 version – isn’t that helped by the presence of a spring loaded inner barrel, tending to push back into the front of each cylinder?
Iain
lain,
I just examined the pellet revolver and I’m pretty sure you are right about the barrel being spring-loaded. But it doesn’t push with any pressure. When the revolver is cocked and the hammer is back the cylinder is loose. When the trigger is pulled, the bolt rocks up and forward to lock the cylinder.
B.B.
B.B.,
Is this a design difference between the pellet and BB firing models? If so, might it have some connection to reports many CO2 Webley MK VI owners report that of the three models, the black, not worn finish, BB model has a lighter and smoother trigger than the others? Interestingly, even the nickel BB version has a heavier trigger than its black counterpart.
Michael
Michael,
I doubt there is a difference between the BB and pellet guns, other than the barrels. Lighter and heavier triggers can be just an individual thing, gun to gun.
B.B.
B.B. and all
Just a little off topic, I saw the large pellets on the Predator International table, makers of JSB pellets and others. I thought they were very cool, see picture below, so I contacted Predator International and got this response;
“Mike,
Thanks for watching the videos from the Shot Show. We had a great time and response was great as always!
The large pellets on the table were made in the CZ and are stainless steel and super heavy. They have become terrific for our use in showing the different styles of pellets we offer. They are easy to see, show and understand.
We had two sets made up and use them both. We will see if additional sets can be made up, but if so it will take a few months to make them and to get them to us. I have no clue on cost but I am sure being hand made they are not inexpensive.
If and when I get a price, I will inform you. Please let me know how many you are wanting and what shapes.
Yours truly,
Dick Dixon
Predator International, Inc.”
Mike
Mike,
Thanks for the info. I see things like that in a lot of booths, but it never occurred to me to ask whether they were available.
B.B.
B.B.,
They just look so cool I had to ask, we will see what comes up as far as pricing goes and I will let the folks know.
Mike
Mike
I use to go to machinst shows in my younger days. They always had some cool display items at the booths.
I have a miniture aluminum slot “mag” wheel that was made on a CNC that the guy at the show gave me. I guess just the opposite of the upscaled pellets. But still cool in my eyes. It was a popular wheel of the day to put on the muscle cars.
What I found when I use to go was just ask. Some would give stuff away. Some didn’t know what to say. And the smart ones said they would try to send something out to me. At least they took the time to take down my contact info.
But yep the thing is it’s unique stuff that not many would even think about having.
GF1,
Yes just cool stuff, nothing real special but I would like some if they become available.
Mike
Intriguing….
Get 12 or 15, in their GTO pattern, slung in a leather belt ‘Chewbacca style’
Maybe it would be better if they sold a mold for these?
Clicky,
I don’t know about all of that, I am just a sucker for a cool nik-nak, these would look cool on the pellet shelf.
Mike
I was thinking about hanging that bandoleer off one end of the pellet shelf, just as a mild bit of understatement
Then just say nothing & wait for someone to ask ‘what gun are those for?’
Clicky,
What gun? The one that really hurts to shoot, I will guess the stainless steel pellet weighs about 3 pounds that would be about 21000 grains, at 900 fps that would be about 37,763 foot pounds. YIKES Hope my math is good.
Yes you make a good point.
Mike
Mike,
Thanks for the update. Very kind of them to reply in such a nice manner. I would settle for some nicely made plastic one’s myself. Same size. Limited editions? 😉
I would have to go for the polymer tipped one or maybe just the classic domed (which I do not see).
Chris
Chris,
You are welcome, If you know someone with a lathe this does not look like a difficult project in plastic, metal or wood.
As he said these are stainless steel, that would be the material of choice for me.
Mike
Mike,
Not sure of the material,…. but there is a bunch of “yard critter” decorations that are solid and have substantial weight. Finished quite realistically as well. That would be my choice of a budget friendly material.
And, just think,…. with a solid, drillable solid plastic material,…. you could add Bear teeth (fake ones),… carbide saw blade tips,.. done in a spiral pattern. LED’s? 😉 1/4″ thick, removable bottom?
Ok,…. I will quit now. 🙂 I am a sucker for cool knick-knack as well.
Chris
The springer project, based on the left front fork from a Yamaha WR450 circa ’03~’06. I got this used from a motorcycle wrecking yard for $50
Mainspring has 30 turns of 0.294″ wire. Wound to an OD of 1.62″ approx, free length 18-1/8″
The inner tube will become the piston skirt, this piston then is going to be 1.807″ diameter. I’m planning on cutting this in half and only using the better condition upper section. That also has a nice synthetic bushing so at least one end of my piston will not actually be touching the compression tube. Maybe I’ll add something to the other end
I’m not sure yet what the stroke will be, haven’t done any maths on that spring, or built a compressor for it
So I probably should stay with a .22 in order to compare to more common rifles, but I think it would be nice if this works for .357 pellets
So I guess I’m in that ‘trying to go big’ camp! But, I’m going to have a burst disk delay valve, in order to maximize available power
Clicky
Well that’s different. Can’t wait to see how that turns out.
But true. A spring is spring and a tube is a tube.
Definitely give more info as you go.
And wonder what the finish weight of that project will be. If it’s heavy that’s not a bad thing if your going to bench rest it. But maybe not so good if your going to carry it in the woods or the feild.
But I’ll just wait and see what happens when you post further info. Sounds like a fun project though.
I’m planning on making this a carriage mount, with no concern for it’s overall length or weight
I’ll save a shoulder fired version for the 2nd or 3rd gen prototypes, should I even get that far with this
If I use a .22 barrel, then I want to get above 20ft/lbs as the goal
Clicky
Then why even bring it up here or do it if your not going to make it usable.
So it’s a abandoned project already before you even start it. ???
Well I wouldn’t call this an ‘abandoned project’ just yet! And having a portable field piece that I carry in a car to a target range doesn’t seem like such a bad idea. I’ve never really been that much of a hunter, having fired 200~300 tins of pellets at paper in my life
Clicky
Give details as you go then on the project. It will be interesting to see.
You’ve got me worried already! And I only just begun rounding up parts for this. I already have enough projects I never finished, as it is
But yes, I ought to have the piston head and a more cut-down piston skirt sometime soonish. I just did a simple spring calculation, and I think it will compress down to around 8.8″, with a half to an inch of preload, then maybe the stroke will be somewhere’s around 8.5″?
Clicky
Why worry. What do you got to loose.
It just might be the world’s best spring gun yet.
I say go for it. 🙂
Well, I haven’t seen anyone try using a burst disk on a springer. So no telling what happens next!
So what does that mean. It’s making to much power.
The only reason for a burst disc is safety if your over powering the system. Do you think you will over power it? And why worry with one compression stroke.
Let it make the compression and see what happens.
The next question is do they make a pellet that will be accurate with all that power you think it will make.
You ever hear of reverse engineering?
Run out of reply, again! I don’t mean the kind of burst disk as used on pressure tanks. I’m referencing their use in Light Gas Guns
For what I am planning, the disk will be placed across the inlet end of the transfer port, and will be designed to break open just as the piston reaches the end of it’s stroke
The theory is that if the pellet were to begin moving before maximum pressure could be reached, then it will never reach it’s greatest velocity. But by having a delay before the compressed air can reach the pellet, then a much higher pressure can be built-up 1st
This will require using a larger transfer port, in order to give room for the burst disk to open. And a bit of experimenting to find the best diameter & gauge, for the disk. There’s actually a never-ending world of design for burst disks. I might be using aluminum from beer cans. Or I might be using mylar sheeting. There’s all sorts of techniques to get a disk to open without creating shrapnel that blows down the works. And all sorts of ways to get the breakage to occur in a predictable manner. I kinda like the two-piece types, where there’s a structural disk placed behind the burst disk, to control where the breaks happen, and to direct the opening movements into a precise petal shape
Clicky
So you will have to replace the burst disc every shot. Don’t sound like fun to me.
And tell me why your worried about making more power.
By the way what kind of air guns do you have now?
Clicky,
Checkout the RSS. I tossed out some ideas. Off to work for now,….. Chris
GF1,
It would seem, Clicky is trying to boost the power by not having the pellet starting to move down the barrel before the piston has reached full travel. I think that is the crux of it. I think he may be onto something.
As for hassle, maybe something like a tap loader? Piston – transfer port – disc – pellet – barrel. A conventional springer break barrel with a tap load (for disc) at the end of the compression chamber/before the pellet would be the basic.
I am not so sure a PCP could not be utilized. Increase breech/pellet depth/seat,.. burst disc behind that (ahead of transfer port). ? Maybe?
Chris
What about a tape roll, that automatically feeds another section each time the gun is cocked? That tape would be the burst disk material
Then a clamping frame that defines the disk working area & act as the seal. Then your breech seal will always be brand new each shot
By the way, somebody very advanced in the SSP arts has been conversing with me via emails that they had looked into incorporating a burst disk into their pneumatic platform because that would solve a slow port transfer issue. But they decided against it as they couldn’t figure out an acceptable location to put such a thing. Then they went on to using another type of solution, so they don’t need to consider the disk. But according to them, it possibly might help a pre-charged setup if that has problems delivering air fast enough
My idea was to use a cartridge system to both have disk and pellet in a cartridge format, and load it like a typical bolt-action rifle. Except I wouldn’t want the cartridges getting tossed onto the ground, so maybe use a belt feed or cylinder & put the fired cartridges back for later reuse
GF1,
How about replacing the standard O-ring breech seal on a springer,… with a burst disc (that also seals on both sides)? That would seem like simplest way to prove/test the theory.
Chris
Years ago, I got rid of everything I had, air guns & heavy machine tools and other stuff, so I could move without a lot of extra baggage. Now I’m starting to get withdrawal symptoms, or something!
The last one to go was an R1 that I bought new in 1992, which I later converted from .177 to .25. I also had a Daisy 120, a Webley break barrel springer in some odd gauge that was a hair bigger than .177, a box load of various CO2 & pump pistols, a Daisy lever action BB gun and my very first airgun was a rusty Red Ryder
But that R1 is really the only gun I ever did anything serious with
Recently, a friend asked me to overhaul some 1950’s era pellet rifles and a Benjamin 137 pistol. So I’ve been thinking more about air power in the last month or so
If all I want to do is lob a pellet with more power, I’d simply get another job and buy a PCP. But I’ve always been more interested in designing things that are not supposed to work, or haven’t been thought of yet
I’m not worried about the burst disk being a one-shot consumable, because it’s not about building the worlds perfect air rifle. It just needs to show the exchange of energy in a unique manner that may or may not be interesting. Kinda like an engineers science experiment. And if it even works at all, I’ll be very happy with it
And I think there’s a possibility to replace the burst disk with a resetting valve that performs the same way. But that’s getting way ahead of myself. I need to percolate some practical hands-on experience before I could picture what form that might take
Clicky
Oh I know what you mean about trying things that people say can’t be done. I have that as we say curse also.
The only way to know is try it and see is what I always say.
But yep just not sure if the burst disc would accomplish anything. Heck it might slow the pellet up. That big hit of air might really try to expand the skirt and cause more drag down the barrel.
Sounds like you got alot of experimenting headed your way to me. And if it does work then you got to shoot at some paper and see if it groups consistently.
After all what fun is a gun if it’s not accurate.
Clicky,
Most awesome! Please keep us posted. You have my interest peaked. 🙂
From your previous post, I had thought that you wanted to combine/introduce some sort of ignitable gas/vapor in conjunction with your burst disc idea? (as power enhancer to the conventional spring gun type)
Good idea on the burst disc maintaining maximum pressure up until the very last microsecond (on a conventional springer type set-up w/nothing combustible).
Chris
Making it burn a fuel would be a form of cheating, and not what I would call an ‘air rifle’. There used to be ether injection air rifles, but those are gone now for the same reason
The engineering challenge is to get more power out of a spring and into the pellet
But, I’m also thinking of totally different projects based on what I learn from this one
I’m already planning the 2nd gen prototype. Now I have to wonder if I’m even going to build the 1st one, or just skip to the 2nd. That’s a really bad habit I have. Got to stop thinking about the next version and just finish this thing!
Clicky,
Ok, sticking to conventional-ish springer design.
The one thing I would share , GF1 took a TX200 spring and continued to chop it (length) until the fps began to drop. I forget the amount, but a significant amount of length was removed. So basically, a longer spring or one of heavier wire will not always translate into more fps. Your burst disc design would be unique, so I can not speak to that in conjunction with spring type use.
Progressive rate springs (varied coil pitch and wire diameter) over the spring length is something you may also consider. In cars, this improves rider feel as the road gets more bumpy/rough.
2nd and 3rd gen, before gen. 1 is built!…. LOL! 🙂 I can relate. Depending on the project, initial improvements are done in the head (and paper) first. I say, trust yourself. Skip 1 and 2 if you are confident. It comes down to minimizing time wasted. Once on something, I tend to obsess day and night. Basically, every waking hour.
Keep us posted. You have me excited as well! 😉 Chris
Did that spring chop include adding spacers to take up the slack? Were the pellets a typical weight for the caliber used?
My burst disk theorizing is based on research I have read, in developing ‘Light Gas Guns’, in which it’s been found that allowing a projectile to begin accelerating before the peak pressure can reach it will severely limit the total velocity
I think this is a very significant factor for why PCP guns are more capable. They do not build-up pressure at the pellet in a slow manner
A very long time ago, I saw in a industrial reader card magazine my dad brought home from work, a different type of spring. It was a flat wire, wound into a coil and bent in a zigzag fashion so it looked like a honeycomb. The alternating flats were designed to rest against each other and slide during operation. This type of spring does not twist at any cross section of the wire, like a standard wire spring. Standard coil springs act like torsion bars. This flat-wire type acts like a leaf spring. The motion in bending is linear down the wires length. The result is a spring that does not try to bow outwards, or vibrate. It’s also capable of compressing much more for it’s free length than a standard wire spring can, with the same amount of force. In other words, it’s possible to get the same performance in a springer using one of these more advanced springs, and have the compression tube made 1/3 shorter, thus bringing the breech back and maybe allowing a longer barrel without making the rifle itself any longer
Another spring idea I’ve thought about is using a stack of magnets that are arranged to repel each other. But there’s much more interesting linear magnetic structures than that. Has anyone tried building a magnetic piston, then driving that with a PM linear accelerator?
Gen 2 means a totally new variable that is not yet worked out. I’m thinking about building this 1st gen so it can be used both ways. Basically, gen 2 means putting the compression tube underneath the barrel and operating it like a SSP. So the new variable would be the totally different transfer port design. Gen 2 or maybe 3 will be the shoulder fired version of the 1st version – which hasn’t even been built yet! I didn’t really want to get started on the next ones until I have a better feel for this power plant
Sometimes, the simplest designs are the best way forwards
Clicky
I tuned several springers that had as much as 5 inches of preload. I cut the springs like Chris mentioned about 1 inch at a time.
I ended up with a half inch of free play in the spring. Guess what else happened. It shot at the same velocity as with all the preload. I even had guns speed up with free play verses preload. And guess what. A smoother shot cycle and more consistent accuracy.
Do you know why the velocity sped up with less spring pressure?
well I hope it wasn’t from reduced pellet skirt drag!
Increased smoothness & accuracy are easy to figure. The springs were operating at a lower stress level
My R1 never needed a spring compressor, even with a Maccari spring. I recall being a bit worried about not using a compressor, but I didn’t feel like fooling around with installing spacers and then needing to build a compressor, so I just slapped it together and went out to put holes in beer cans. Far as I could tell, it worked just fine. Too bad I didn’t have a chronograph, but the ballistic trajectory told me it was faster. Less drop at 70 yards vs 50, than it had before
Clicky
Nope not from skirt drag.
It was because with the extra power the spring was making it was pushing the piston faster than what the seal could hold. In other words blow by.
And yep it was new piston seals. I even experimented with different size o rings instead of the factory seals. When the right fit was made the piston moved fast enough but didn’t allow the blow by. So more power could be made with a slower piston movement.
Doh! Didn’t even think of that! And yet another part I have yet to decide on, too
I’m probly gonna be up late looking at seals now…
Clicky
Well what did you come up with on seals?
Had to sleep a bit, was 2:30am here. But there may be more nights spent just on seals
The barrel will be more like an under lever gun, except that it will slide forwards to allow the transfer port assembly to be changed out. So the breech seal can be something more aggressive like multiple o-rings on the outside of the barrel, inserted inside the transfer port assembly
I’m thinking maybe I better build the piston head so it also can be changed out easily
And maybe I already have more power just in terms of the increased bore, I don’t need to move the piston any faster than what works. So I’m breaking the design down a little bit further. Spring force vs air pressure is how I had been thinking of it. Now it’s going to be Sf(spring force) vs Pa(piston acceleration)/Pa vs Seal/ Seal vs Ca(Compressed air profile)/Ca vs Tp, or Bd(burst disk) ect…
Chris
I just replied to clicky above. But not sure if the burst disc would be a benefit. I’m thinking if the air is released abruptly it could expand the skirt slot and cause drag down the whole barrel. It might actually slow the pellet up.
And another thing is will the disc burst repeatedly at pressure that would fall in the range to keep shot to shot spread small.
I think the burst disc is one more variable to add that could cause more problems than help. You know my saying. Simple but effective. That’s the way I like it.
Yeah, been thinking about that variation in burst pressure. But it’s what I’m going to try. Besides, I think the resettable valve design should be more consistent than a burst disk
So the only benefit I want to see is increased power. Then I can try getting it consistent later
Besides, I am of course going to be shooting without a burst disk. At least half the shots should be comparison rounds to compare with & without, for different port shapes & spring settings
On the other hand, there are precision burst disks out there, so maybe another way to look at those is they could potentially make the spring & piston operate with more consistent power
Like a shock absorber on a car suspension, the valving provides control over how the suspension feels
Clicky
Heck maybe you can design in a electronic adjustable dampener like some of the cars use with their shocks and struts to tune how they ride.
Now that’s a system I would like to see on a springer. Well I guess we should call it a niitro piston control.
Now we are talking. I always said that was a reason I didn’t like nitro piston guns because you couldn’t tune them. If the electronic dampening was incorporated you could have a tuneable gas operated piston.
I like that. Now it just needs to happen.
Possible, but an electronic system will require power
I think a tuneable nitro piston will be an entirely different project on it’s own terms, but maybe that could help with what I am thinking of doing
If that works, then it should be possible to have a microprocessor-controlled piston speed monitor that adjusts a mechanical valving system to slow the piston as needed, in order to prevent overspeeding, and to prevent variations
Then it won’t matter if the spring itself is ‘too much’. I was just now thinking: hey, this damping concept might be what all those overstressed chinese guns need…
But I like the damped nitro idea better
And while were going that way, why not have a bluetooth module in the stock that communicates with a phone app you would install for free. Then be able to change settings for each pellet, on the fly while out in the field
Wonder if it’s worth trying to use inductive braking, like an eddy-current chassis dyno, to recharge a battery for the electronics
Clicky
Yes that’s it. Even a smart phone app. I love it.
This is just way to much. Or maybe not.
There are air guns that already have used computer control for some time now.
But I have to say this is the first I believe I have heard of controlling a nitro piston with a electronic valve and computer.
I think this idea is way over the idea of your burst disc idea.
I say build it and they will come. 🙂
Yup, was just thinking ‘oh darnits, working on wrong project again!’
But building nitro pistons isn’t to be taken lightly
And building a fast enough feedback & control loop is another challenge
Then the interface software
And the ECU will need several different things going on inside. It might be a good idea to have a simple control interface on the outside of the gun, to allow choosing presets without needing to drag out the phone or laptop. Just look at what the upper end of paint markers are doing. Those might have already set the acceptable standard for what sort of electronic device ought to be visible on a gun
And why not have this for CO2? Can’ts we also have our bluetooths for custom velocity profiles on a CO2 blowback pistol? Something about that just seems very appealing
Crikey, a new project, like always!
Ok, so how does one go about building a nitro piston? Are there any teardowns? Reverse engineering blog reports? What material is used for the seal, how much pressure is it charged with
And lets make this retrofittable to all existing springers
But I really want a ceramic barrel! Can’t I anyways? Reminds me of yet another project. I need a vibratory brass polisher & corn media. Then degrease my pellets and toss those in there along with some 5-micron hexagonal boron nitride powder. That will allow burnishing the barrel with HBN. The barrel will never be the same again after that. Of course, need to thoroughly clean & degrease the barrel 1st. And it needs to be fired dry in order to get the coating to work right. 100 pellets like that, then go back to normal oiling and untreated pellets. That technically constitutes a ‘ceramic barrel’
https://patentimages.storage.googleapis.com/ab/f7/c6/62e921962cb3ea/WO2012096869A2.pdf
I think Crosman already knows how to do most of it
If the damping system used an electric generating method to act as a velocity sensing feedback, ie the faster the piston moves/the higher the signal, then use a mechanical damping device actuated based on the feedback return generated by the microchip. And to use a fast enough microchip that you can have enough velocity control update cycles to get about 200 or so control points along the spring travel
This might be something for Crosman to look into. So lets just make the general concept an open-hardware license. So, lets see now, 3 years before we see this hit the market? Anybody up for beating that?
Clicky
Prove it and it could happen sooner.
Clicky
No ceramic barrel. But check out the Daystate guns. They got some cool guns that do stuff with electronics. And of course the Benjamin Rogue.
Lloyd Sikes that use to comment here developed it. Then Crosman took it and changed things around. It wasn’t the same gun after that. It’s a shame because Lloyde had a cool design.
Clicky,
Interesting conversation between you and GF1. For me, I would get a springer (break barrel) and sandwich 1 or more layers of aluminum foil at the breech seal. Pre-score if desired. At least that would test the theory in an air gun. FPS up,… or down? Simple.
On scoring,… take the material and put something lower (less height) around it and press down with a razor blade. That sets the depth of the score.
You sound very well versed in many things. Good. The only thing I can offer is researching (all) that has ben done before that is (similar) to what you are doing. More than a few times, (here),.. I have come up with some “EARTH SHATTERING, GROUND BREAKING” idea,…. only to have B.B.,.. or others,.. “whip out” a dozen or so links that clearly shows that someone (before me) has been there,.. done that! 😉 That,.. “Sir”,… is one reason I recommended this blog and the people here to you. Lots of good folks that will be straight shooters with you. And,… some didn’t just come down in the last rain storm either. 😉 Simply put,…. a smart bunch is to be found here.
I (do) admire your enthusiasm!,……….. Chris
Clicky,
Also, if you are interested in electronically controlled/regulated and fired air rifles,… check out Daystate as they have several models and seem to be/have been at the forefront. I have a Red Wolf, High Power in .25. There is a programmer for them as well. I know little on the details of the tech.,… but I sure do love it.
Chris
Clicky
Heck with the feed back loop. Set the velocity up or down on a digital screen and then shoot that nitro piston gun.
And why not a electronic adjustable valve on Co2. It’s the modern electronic time. I would like a push button Co2 gun as well as a nitro piston break barrel or even a underlever nitro adjustable valve gun.
And as far as pcp’s it’s already been done. But maybe the electric nitro or Co2 gun might be something for the future. Of course if the bugs are worked out if they come to market. And the way they are presented is another thing and it better be well made. Oh and most importantly. Accurate
If it’s not accurate, then somebody gets to walk the plank…
Feedback loop is absolutely required to allow ramping profiles
In order to maintain a consistent pellet velocity, the damping needs to alter it’s valving on-the-fly, and that can’t be done without taking a measurement & calculating a new damping factor multiple times throughout the one single shot cycle. Maybe the number of control points doesn’t need to be so many? Depends on how quickly the piston can change speed when left uncontrolled
Actually, I would like to see if I could make the barrel out of plastic or non-ferrous materials such as ceramic. Then have electromagnetic pickups at several locations down the barrel in order to monitor actual pellet velocity. That might be a much better source of control points for the feedback loop
I’ve already tested this idea out with my R1. One day, just for fun, I set a Garret 250 metal detector with the standard coil, behind a shield made of plywood. It was setup so I could shoot very closely right across the coil. Then I set the detector to it’s maximum setting and set out to see just how far away I could shoot and still get a beep out of it. The 250 has a really annoyingly loud beep whenever it registers. Loud enough you can hear it from 50 yards easily. I was able to get about 5 or 6 inches away from the search coil and register 100% of all pellets fired. I was thinking at the time about getting a 2nd detector and make a chronograph based on that. But that’s yet another project
Clicky
Search Pyramyd AIR blog + what subject your looking for and you should find your answer.
But be prepared to do some reading. Lot of blog and comment info is all I can say.
Let me know what you think. But I do believe you will find some interesting info.
Clicky
Even if you get your ceramic barrel and you boil it and saute it.
Don’t forget to soak your pellets in beer. See how they group the next day. If they are still sticky when you try to load them in your gun you didn’t wait long enough for them to dry. Try again after they dry.
Top secret info here. And try different beer and see what happens. 😉
http://www.davidtubb.com/bn-boron-coating
And I always try to test different beers out on the range. The newer style screw top Budweiser cans hold up better and are a bit smaller diameter than traditional cans. My standard setup is to place a can on it’s side with the bottom end squarly facing the shooter, fine sand all around the can to show any flyers. This will always be at 50 yards. Any shot that makes a nice tunk on the can is a good one. Flying sand is a loss. So my scoring is very simple, a point for tunks, no score for sand. 10 shots per round. Strangely, none of my friends ever go shooting with me…
Got a bit sidetracked, but some interesting infos buried in this report: https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2016/armament/18355_Armstrong.pdf
Thinking about using that active cooling system on my bikes exhaust in order to vent the crankcase fumes into a catalytic convertor. It would have a check valve added right before the venturi
Yeah, yet another project. Designing my own muffler & exhaust, using some flow physics that haven’t yet been applied to mufflers
GF1,
Beer sauté?,…………. One more thing you have been holding back on me? 😉
Does tossing a few (pellets) back like MM’s, holding them and taking a swig of brew count? No pellet holder needed! Then again,… I think I read something about lead exposure/ingestion being not so good for a person. Bad idea. 🙁
So,… details????? Light, dark, full hops, Lager, Stout, Pilsner???? I do not think that beer would better than some sort of lube/solvent/synthetic liquids. Yes? No? Details Man! 🙂
Chris
That ‘been there, done it already’ thing is why I posted here to begin with
Daystate has the lead! What they are doing is exactly what I would attempt with a software controlled nitro piston
Their own description of the MCT, Mapped Compensation Technology, is described as controlling each nanosecond of the shot cycle. That means they are using a very fast microcontroller, likely with very finely optimized firmware that is designed to have the least amount of delay possible for each control point cycle. Their solenoid valve will also be worth studying, as it may be a careful compromise between durability & response time
I think a nitro piston will have enough inertia that changes in velocity will be slow enough that Daystates MCT tech would be very extreme overkill. Unless the piston is made as light as possible….
They refer to ‘Mapping’. This is what I mean by ‘ramping profiles’. They are probably using a lookup table that’s tuned for a particular setup. That controller will allow editing the lookup table so you can change how fast or slow the air is delivered at each point in the shot cycle
But what I would want to do is skip lookup tables and have a learning algorithm that only needs to know what the pellet weight is and how much velocity you want to give it. Then the software would simply make sure that every shot is the same. This means that a PCP tank would not need to be regulated, as the regulation would be done in software
The HTU, Hybrid Trigger Unit, is exactly what I would want for my target shooting designs. That’s basically a fly-by-wire sear release. Kinda straight forward actually. I could mod a Record trigger to act as the signal input for something like that, then have whatever solenoid I like to do the actual sear release. That would be a natural extra feature to include on a soft-nitro gun, seeing as it’s already going to have batteries & stuff going on inside. I would only make just the one small change to that HTU. It would operate wirelessly from a separate handheld control unit. The gun itself should be on a servo-driven tripod, like the T.R.A.P. system
Clicky
Alot of the stuff your talking about has been done already. But not with a Niro piston. I think it’s something you should try.
Go for it and let us know what you come up with.
Chris
You asked about the beer and pellets. If you talk to Buldawg still ask him about it. I’m sure he will remember.
Oh what the heck I’ll tell ya. One day I happened to spill a beer in my tin of pellets. Well I emptied the pellets out and then let them dry on a paper towel overnight. Then I shot them. Guess what. They shot better.
And this is a true story. But I don’t do it to my pellets. Hmm maybe I should. 😉
BB,
What is the purpose of the wing shaped things that poke out on each side of the frame, inline with the cylinder’s axle? Also, in your closeup photo of the bolt, the one with the yellow arrow, there appears to be something sticking up through the frame at the end of the word “WEBLEY”. Is that engaged in what appear as Woodruff Key slots that are arranged around the cylinder’s periphery? If so, what purpose does it serve, if the bolt is what locks up the cylinder, and at what point does that thing engage the slot? Don’t know much about actual firearm pistols so this is all new to me. Thanks for choosing to cover the firearm and the CO2 gun together.
Half
I was wondering the same thing about the ‘wings’
Stabilize the cylinder?
Get the gun to more easily return into it’s holster?
Hidden bayonet nobody knew about?
Half,
I think you want to look deeper into the Webley Mark VI revolver. The Brits don’t call things the same as Americans, so what I call the bolt (a Colt term) they call a cylinder catch. Just as good, but not the same. That Woodruff key appears to be a secondary bolt. I would have to study the drawings to tell you why it’s there, but the bolt I showed it the main one.
The wings are one piece with the barrel and seem to prevent other parts from moving beyond their limits.
B.B.
Nice original Webley you have there, Sir! For the history buffs, who would experience the period when aforesaid revolver was in active service, you might want to head here – https://www.theguardian.com/film/2018/nov/11/they-shall-not-grow-old-peter-jackson-review-first-world-war-footage
1916…the awful year of The Somme.
B.B.
It’s been a long day, so I’m “late to the party.”
Yet I found this bit fascinating:
“The Webley bolt (arrow) rocks up and forward a few hundredths of an inch to lock the cylinder in alignment with the rear of the barrel.
The pellet gun uses the same technique for locking the cylinder and indeed locks up even tighter than the firearm.”
I love these historical blogs! I learn so much. =>
Thank you,
dave