This report covers:
- The start
- BR-50 and Gary Barnes
- Not all were smallbores
- Splatology
- USFT
- Benjamin Discovery
- More shots per fill
- Summary
Today we discuss the physics (or fisiks) of lower pressures in precharged pneumatic (PCP) airguns.
The start
Reader RidgeRunner has been telling us for years about the low pressure to which he fills his AirForce TalonSS and yet still gets a reasonable shot count and great velocity. Let’s start there.
BR-50 and Gary Barnes
Many years ago Gary Barnes made a traditional sporting PCP that I wound up with. I gave it to my wife, Edith who used it to compete in the sport of BR-50 (it was called BRV when she started). It was incredibly accurate but equally interesting was the fact that it operated on just a 3000 psi fill, or less. Less, as I recall.
Edith competed in BRV with a .177 Barnes Ranger PCP rifle.
Gary Barnes made this special offset scope mount so Edith could sight with her left eye while shooting right-handed.Those two outriggers adjust independently and the scope rings swivel to align with the scope tube in any orientation.
Not all were smallbores
Gary Barnes experimented with lower pressures in big bore airguns as well. He discovered that just 500 psi was enough to power multiple shots of a large-caliber rifle. He was fascinated by the Girardoni that apparently shot no less than twenty-one .47-caliber—11.93mm balls fast enough to kill a man at over 100 yards.
We don’t know for certain how high it was filled but tests of actual hand pumps and replica Girardoni air reservoirs (that Bartolomeo Girardoni used as the butt of his repeating air rifle—hello AirForce) could not have been pressurized to over 800 psi and more likely 600 psi, or so. Of course the modern chronograph did not exist in Girardoni’s time but for velocity we have the ancient equivalent of splatology.
Splatology
Splat-whatagy? Splatology is a term coined by Gary Barnes to describe what round lead balls look like after they hit a hard target. Barnes tested his big bore rifles in a wooden shed on his suburban property that was both a workshop and his testing station, so he shot against hard steel targets to keep the neighborhood safe. From this he noticed a correlation between the velocity of the lead ball and the size and shape of lead “splat” it made after hitting steel.
Every splat tells us its impact velocity, if we know how to read the signs.
A .535 cal. ball penetrated this 2×4 board and still hit the splash plate at over 500 f.p.s.
If you want to read more about splatology, read this report.
USFT
Then there is the USFT rifle that I have reported on many times in this blog. Mine fills to just over 1,500 psi and gets a velocity of 900+f.p.s. with 10.34-grain JSB Exact Heavy pellets. And that fill is good for 59 shots. And the USFT has NO regulator!
USFT rifle.
Of course the USFT has a huge reservoir that accounts for all the shots. However the valve and the valve alone accounts for the consistency of the shots.
Benjamin Discovery
I’ll finish with the Benjamin Discovery that started the price point PCPs in 2007. It filled to 2000 psi yet got 20 good shots at 1,000 f.p.s. in .177. For years Crosman offered variations of PCPs on that theme, but they are now gone and the marketplace has abandoned lower-pressure air rifle. Why?
More shots per fill
With a regulator and a higher fill pressure we do get more shots on a fill. They don’t go out much faster (or any faster in the larger calibers) but apparently shot count is an important sales point. Are we heading in the same direction that cheap spring-piston rifles took when they were sent to China? Is shot count today’s equivalent of velocity bragging rights?
We know that velocity is meaningless past the accuracy point. At what point does shot count become equally ridiculous?
Summary
Today’s report is just food for thought. The market isn’t going to change for two or tree hundred vocal customers. They sell to thousands and they have to if they wish to remain in business. But isn’t it nice to know that PCPs can be made that are friendly to hand pumps and don’t drain your air tanks?
“Gary Barnes made this special offset scope mount so Edith could sight with her left eye while shooting right-handed.”
BB,
Those two pics of Edith and her rifle were the most interesting things for me in this report.
Could Edith shoot accurately at only one set distance with that offset scope?
Or did she have a table of scope adjustments for different ranges?
That’s quite a rig!
Blessings to you,
dave
Dave,
Yes. Because of the offset of the scope’s sight line it could only be zeroed at one distance.
BB
BB,
Thank you; now that I’ve had my morning caffeine, I can see what I should have seen last night. 😉
Blessings to you,
dave
Shot count is popular because we all delude ourselves we’re going to have that extended plinking or pesting session that rarely actually happens.
Ohio, I don’t know about that..
When I get to plinking, it’s almost always at least a tin of pellets.
There’s a reason I have 3 carbon fiber bottles…
Ian.
Ian
“The market isn’t going to change for two or tree hundred vocal customers. They sell to thousands and they have to if they wish to remain in business.”
I wonder if it’s typical for these thousands of people 3 carbon bottles and a tin of pellets per session. I believe that in real life this kind of customers would be best served with low pressure PCPs. But then there’s the ugly face of marketing.
Bill,
Airguns are like automobiles. It costs just a little bit more to build an air rifle that uses high air pressure with a high shot count than to build an air rifle that operates on a low air pressure and only gets twenty to twenty-five shots on a fill. The customer dreams of going to EBR or such and competing against those folks and winning. “That is what they use. That is what I want.” The marketeers are more than happy to sell the unwashed masses overly priced airguns.
Just as they are happy to sell them a 6000+ lb Hummer or a Monster-sized Truck which will rarely be used for their alleged intended purpose. FM remains happy about not having to deal with a lotta drama getting the “Max Brothers” filled up for a pleasant shooting session. Do admit to recently acquiring a relatively inexpensive PCP electric air pump which makes for an even easier pumping session when you only have to go to 2000 PSI.
Ian,
If your air rifle operated at a lower pressure, you could fill it more often from those three carbon fiber bottles. I bet it works out to about the same number of shots. Physics is Fisiks.
I understand where you are coming from and I rarely fill most of my PCP’s to max
I only have one “large” 60 minute cf bottle, the other 2 are the smaller ones about the size of a 2 liter soda bottle.
The only rifle I use regularly that I fill to max (3600ish) is the Umarex Zelos as the regulator is so stable across the entire shot string.
The others I fill to about 3200ish as that is where the regulators on my Avenger series are most stable.
I CAN shoot my Texans at 3000 psi fill, with slugs. But the shot count is low at those hunting velocities.
But I plink with my .457 Texan at about a 2000 ish fill, with.457 round balls instead of 365 grain slugs for hunting.
With the slugs, at 3000 psi, 5 shots is it at hunting velocities,.
With the .457 round balls, at 2000 ish psi. I get over 10 shots accurately out to 50-75 yards. Stopping around the 800 -1000 psi area.
One of the smaller bottles is regulated to 3000 psi output. I use that one when I am letting friends shoot the Texan as they cannot accidentally over fill it.
Ian.
45Bravo,
That Texan shooting the .457 round balls sounds very cool (to me anyway). With black powder, I always have loved the ball better than the rest. Just something about a round ball. Glad it’s working for you. Only round balls I have shot out of an air rifle are .177. I’ve had no luck with those Gamo or Beeman lead balls. I was thinking maybe the Air Venturi H&N Excite Copper Plated maybe better? I’m talking about a higher power break barrel of pump, not the low power bb guns.
Doc
45 Bravo
” ” DITTOS ;^)
shootski
Tom,
I wonder if the failure rate of these High Pressure PCPs are just anecdotal on your end or if it is a reality that is catching up with everyone who own one? Will this possibly lead to a return to lower pressures or to PCPs that are built for easy maintenance?
Siraniko
Siraniko,
I hope it is at least considered.
BB
Siraniko,
There is a reason for the extra o-rings being included with a new high pressure airgun.
The folks who purchase these overly priced high pressure airguns are not going to work on them themselves. They can afford to send them off to be fixed.
I do hope and dream of the return of “low” pressure airguns. TCFKAC was starting to realize that and return to such. Let us hope that the Gamo marketeers do not ruin such.
RidgeRunner,
I agree the Pressure Wars are a joke; even in Big Bores.
Anything above 250 BAR (3625.94 PSI) is a nearly complete waste of Work done to get that pressure; according to the correct understanding of the Gas Laws for non ideal gases of which air is a Prime example..
shootski
shootski,
Even that pressure is a waste of effort. Air rifles used to operate at under 1000 PSI and get over twenty shots in big bore. I think the manufacturers need to take a long, hard look at where we have been and where we are going. Something seems to have been forgotten along the way.
They forgot about longer barrels….
RidgeRunner,
Totally!
Unless you want to do the deed at a FAR greater distance and/or a thicker skinned beast…with Certainty.
shootski
What kind of pressure was used way back when?
RidgeRunner,
I have tried to find written accounts that could clearly establish the maximum or typical pressure that was used in the 17th Century and after with no success. I believe the Smiths built pumps and reservoirs to the best of their ability with materials available and likely just pumped until failure or the level of performance that was adequate. I can see of no way they would have done direct measurements beyond some estimations…but so little was likely shared and was probably held as SECRET to keep their Trade safe.
The pressure numbers we have come from recent attempts done by building replicas. IF there are SECRET techniques the Smiths used we will likely never know exactly how much more they actually achieved.
Reverse engineering is a very difficult task in almost anything old or new.
shootski
Give it to Uncle Xi’s buddies. They are very good at “reverse engineering”, most especially after they have stolen the original plans.
I found this offset scope mount very interesting idea.
Talking about ideas…
There is a 3D printed palm rest on my FWB800 which makes a great job. I would never believe how good this is.
“T[h]ree hundred”?
Physics is phun!
B.B.
“We know that velocity is meaningless past the accuracy point. At what point does shot count become equally ridiculous?”
When you run out of loaded magazines and you have to refill the magazines in the field…IMHO.
-Yogi
Yogi,
I am hoping your answer is rhetorical.
Where I live, there are bag limits per day for game species.
Maybe he’s mini-sniping.
Yes, but how many shots do you take before you get a hit?
-Y
One.
One if I take my time.
So ditch the magazine and get a single shot loading tray!
-Y
Or just make it single shot to begin with.
I think we are beating a dead horse here.
The unwashed masses wanted higher velocities so they were given higher velocities. It did not matter that they could not hit the broad side of a barn while standing inside. Those who were shucking out the bucks wanted higher velocities so the marketeers and manufacturers gave it to them.
The new thing is shot count. Now that regulators work better and do not add that much more to the cost, the marketeers and manufacturers can jack up the fill pressures and give the unwashed masses what they think they want. The cost of the regulator can be offset by a simpler valve system.
The higher air pressures also allow the barrel to be shorter so the projectile can achieve higher velocities. So what if you have to put a suppressor on the end to catch the excess air and hopefully quiet the airgun down a bit? The barrel is still short. That reduces manufacturing costs. You have to buy the suppressor separately? Who cares. You’re rich. Besides, it is exciting to own a real live suppressor, even if it is just for airguns.
Besides, we can all afford expensive air compressors and numerous carbon fiber bottles. Who wants to use a hand pump anyway?
I am done beating that dead horse now.
Go on, my friend. We don’t mind, and neither does the horse. ;o)
The horse indeed does not mind. It is dead.
I am tired though.
And it had no name.
Beating on it does no good. It does take more energy than I have though.
I’d say that shot-count is determined by what the shooter is doing at the time.
My (frequent) extended plinking sessions can run into multiple cans of pellets so I favor my bottle-guns and larger magazines to minimize the interruptions involved with refilling.
I keep an airgun by the back-door and make a point of shooting at least a couple of shots “cold” (to stimulate a hunting situation) every time I walk by. All my airguns (by a lottery system) get a turn by the back-door, again, more shots and larger magazines are best for this activity.
When testing and tuning I shoot 5 targets of 5 shots, top off the air, run a couple of swabs through the bore and review my notes. I’ll then shoot 5 shots the stabilize the plenum, valve and bore before proceeding with testing. Since most of my shooting starts with a fully charged, clean and stable gun, this routine reflects my typical usage, and gives me a chance to relax and regain my focus between sets.
Shot-count doesn’t matter if you’re hunting… you only need one shot – right? The local bag limit is 6 squirrels and 6 rabbits a day, I never take more than two so all of my PCPs have way more capacity than needed.
Walkabouts are the only time that shot-count is a concern for me. I’m away from my refilling station and do a lot of shooting at targets of opportunity. I can (easily) go through most of a tin of pellets on these outings so I leave my PCPs at home and take a HW30 or FWB124 springer. 🙂
So, my take on shot-count is that more is better, if that takes a higher pressure fill then that’s fine by me. I rarely fill to maximum pressure anyway but it’s nice to have the option if needed. As far as higher pressure meaning more problems/leaks, I have had a bunch of PCPs for quite a few years and haven’t had any issues.
Cheers!
Hank
BB,
Today is a great example of why I regularly read this blog.
Starting off with some history, some explanations of ‘why’ and some current examples of the topic.
Then, the comments section that lets the readers share how they operate (with an incredibly varied outlook) and show us how they enjoy this great sport.
It all comes down to how we each find joy in this hobby of ours, and if we aren’t enjoying it, why are we doing it?
Here’s hoping that you find the joy in whatever you do today.
Bill
Billj,
My hope is built on nothing less…
BB
I, like RidgeRunner, like the idea of lower pressure fills. I can only think of two or three 2,000 psi guns. I wish PA or somebody would compile a list of higher fill guns that work great on lower pressure. I think BB has said Air Force will and a couple others that slips my mind right now will do that. I figure, as other stated, the high velocity crowd will think higher pressure must mean more power.
Doc
Doc,
Most .22 caliber PCPs (the typical 30-33 fpe standard models) are regulated to 120-130 bar so a “low pressure” fill of 200 bar gives about 75 bar of useful pressure. Shot-count is dependent of available volume and the tune.
My PCPs have 200, 230, 250 and 300 bar fill ratings, just because you can fill to those levels doesn’t mean you have to. As long as the fill pressure is above the regulator set point, you are good to go.
Don’t let the maximum fill pressure rating turn you away from a PCP that you like. Just make sure that you’re not buying a high power 60 fpe airgun if you’re wanting a calmer, quieter one. That or buy one that’s adjustable and tune it to what you want/need.
Cheers!
Vana2,
Well said!
shootski
Vana2,
Thank You Sir. Yes I knew some could, just didn’t know which are better than others. I will also say some must shoot ok under the regulator set point too. Example is the Umarex Komplete. The Komplete is designed to work on Nitrogen regulated to a pressure of 1,800 PSI. Yet it does well with C02 that is generally 800 too 900 or so PSI. Hmmm.
Doc
Doc Holiday and Readership,
There are far more than two or three airguns that CAN shoot well at 2,000 psi!
This is where i get to do some ‘splayinin’…
Even my unregulated .58 Caliber DAQ Pistol and Shortrifle can shoot well on a 2,000 psi fill!
My Benjamin Marauder in .22 caliber tuned for hunting can shoot well on a 2,000 psi fill as well.
My Benjamin Discovery by design shoots well on a 2,000 psi fill AS ADVERTISED!
Those last two words are the key to the problem AS ADVERTISED should mean almost nothing to an air gunner! We have apparently become slaves, all to often, to the words of the Marketing types that they put on the outside of the box and in the advertising. Most airguns to include regulated ones with Carbon Fiber reservoirs will only use 2,000 psi or less, sometimes much less, to launch a projectile well. It comes down to a small number of considerations we all need to think about:
1. Shot Count needed
2. Projectile choice
3. Muzzle Energy (ME) desired
4. Retained Energy at the terminal point.
If you are still with me my .58 caliber airguns shoot well on paper/Steel with a 2,000 psi fill and a tune that supports launching a 283 grain .575 lead ball out to 90-110 yards. However If i want to shoot a .350 grain Hollowpoint bullet (slug) at a Boar (Pig) i will want more ME and retained Energy in/at the Boar. That takes a higher fill to 3,600 psi and a few changes to the tune to get the MAXIMUM the DAQ design is capable of.
YOU decide what YOU want!
YOU get to decide what YOU need to get the task at hand done!
YOU need to know all that BEFORE you read a single word on the box or out of the Marketing types mouths.
YOU will then be able to see past the hype and recognize that most airguns can and will shoot well at ONLY a 2,000 psi fill.
This blog and a few other spots on the Internet and elsewhere are islands of more FACT than Fiction.
So thank you Doc for the opportunity to get on my box and try some preaching.
shootski
PS: Not all too many modern airguns will do well on a 600-800 psi fill…but there could be IF buyers were smarter…that reminds me:
“Three great forces rule the world: stupidity, fear, and greed.” Albert Einstein
Shootski,
By all means, preach on! I haven’t went to the dark side yet. But you are building my faith in it.
Thanks for the info.
Doc
Anybody know of a source for ‘new’ .22cal BB’s? Found some NOS lead shot. Thinking of getting a vintage airgun.
Decided on a .177 P Five, lower cost ammo with longer plinking range. Also ordered a Ruger Mk4 spring pistol for possible in-home shooting. Would like to check it out. Added a reflex DOT sight to reach free ship.
If they are .22 caliber lead balls, they wouldn’t be called BBs, they might be called shot or round pellets. Here’s one offered by P.A.:
https://www.pyramydair.com/product/gamo-round-22-cal-15-43-grains-lead-balls-250ct?p=610
I have no experience with them. But as part of a lot of airgun ammo I ended up with when I bought an airgun at auction, I have a bunch of .22 caliber Beeman “Perfect Rounds,” which I belive were manufactured by H&N. I have not shot them yet, but you may want to see if they are still made.
I also found some at JG Airguns:
https://www.jgairguns.biz/2600-c-78_84_660/rb22-22-caliber-round-lead-balls-for-airguns-p-8232.html
You might also try a search for “rundkugeln 5.5mm”
That brings up some links to German and other European stores.
Good luck!
Roamin,
Thank you so much. I should have known better and checked with PA first.
I don’t remember this at all.
Healthways Plainmaster .22cal. CO2 air pistol. Model 9406. ( lead ball ) it is all original.
I have never seen this type of air pistol. Looks cool.
Roamin,
BB did a 4-part blog on the Healthways Plainsman starting back in 2009. This was a .22 variation offered back in the day. It came with the removable forward grip and is called a Plainsmaster.
Main highlights, three position hammer spring adjustment screw bottom of the grip. Back of receiver slid up to pour in bb’s. CO2 cartridge plunger is in the end cap, upside down from most today. I never did a power check but on high power it was surprisingly powerful. This one has a longer barrel as well so the performance may be different.
Not too impressed with the front grip but it’s now part of airgun history.
Do want a really High shot count? Just lower your energy output per shot . Some of the air guns for UK with a 12 ft-lb limit will get shot counts greater than 100 + per fill. They typically hunt rabbits, squirrels and pigeons with that limit. You do have to practice to take your target critter with a single shot. But those guys are good at taking pests down with just 12 ft-lb.
It is just a matter of shot placement and practice. Yes I fell into that trap with first PCP Airgun as an adult, until I came to my senses hunting squirrels with a 8 plus lb airgun shooting 30+ ft-lb was way more than required to get the job done and way to heavy to carry very long. My Prod tuned to about 14 ft-lb and weighing in at 5.1 pounds with red dot , light and additional silencer. Both very quiet and very effective out to 25 or so yards, and light enough to carry until I am done shooting. My Prod has a huma-air regulator and gets 21 very consistent shots. Without the regulator I was getting 14 consistent shots and 14 more that were ok.
Mike
Collecting Air Guns.
That Healthways CO2 pistol pictured above was part of the Robert Beeman collection, as in Beeman Airguns. The Brass tag.
From what I believe, he had over a thousand airguns. That actually makes me feel better because I will never possess anywhere near that number. And evidently, he did not do a good job of maintaining them. My fingers are crossed. How could he possibly maintain that amount.
I got to thinking, why so many? Best I can figure acquiring airguns can be a form of entertainment or you can call it a hobby. Acquiring them, not really shooting them. Instead of going to shows, events or out to expensive restaurants spend your money on airguns for fun. Might be the equivalent of a woman’s desire to window shop for shoes?
Granted this kind of behavior is probably restricted to people with deep pockets, but the desire may be widespread. It’s a big part of collecting anything. It pleases to acquire and possess things you enjoy.
Acquiring a thousand airguns probably had absolutely no effect on his financial affairs if you have managed well. Same with Charlton Heston and his firearms collection. It was just spend money… Being spent!
And actually, it’s not wasteful spending too much if you can return them into cash by selling them off.
But think about it, if you can easily afford this kind of extravagant behavior, you probably never will need to sell anything off … and the rest of us get to acquire it when your estate gets sold off.
Kind of like a natural path for preservation. An important role collectors play.
In my opinion, his vast airgun collection should have been turned into a museum of airguns, where they could be preserved and shot for fun by visitors.