by B.B. Pelletier
Test and photos by Earl “Mac” McDonald
Time for something different, but useful just the same. Mac used these Leapers UTG 30mm Quick-Detach scope mounts when testing the RWS Diana 350 Magnum rifle, and he fell in love with them. He told me that he would definitely recommend them to anyone. Let’s see what he has to say about them.
Leapers UTG Quick-Detach rings are made to install and remove rapidly.
These are two-piece rings that fit onto Weaver and Picatinny scope bases. But these are rings with a difference. Each ring has a tensioning lever that snugs the ring down to the base in one quick, easy movement instead of tightening several screws. And why is that so important, you ask? Because it allows you to switch the rings, and therefore the scope that’s in them, from airgun to airgun in a matter of less than a minute. Boy, do I wish I had owned 10n sets of them back when I was doing heavy airgun testing! Heck, I guess that day hasn’t passed yet.
Let’s look at the rings now
These rings are made of aircraft-grade aluminum and are hard-anodized dark black. They have no-slip liners to grab onto the scope tube. Mac got both the low- and medium-height rings, but since he was mounting to the Leapers UTG Weaver scope base made for a Diana 350, he already had all the height he needed for a big scope. There was a half inch of clearance between the 56mm scope objective and the rifle when the scope was mounted. So, he tested the low rings. Speaking of that, when was the last time you even saw a pair of low scope rings? They’re not exactly common.
The low rings have four-screw caps, but the medium rings have six-screw caps, if you can believe it! They’re built as rugged as you want them to be. The medium rings say they are a see-thru design, but the hole in them is nothing more than a lightening cut. You can’t really see the open sights through it.
The rings have a steel key or insert in their base that conforms to the cross slot of the scope base they’re mounted upon. When that butts against the back of the slot, the rings aren’t going anywhere.
The half-round cross pin fits into the cross slot on the base.
The quick-detachable part is the best part of these rings. Each ring has a cam lever on its base that pushes a movable jaw when it’s cammed shut. That’s what keeps the rings attached to the base. An adjustment screw in the center of each ring lets you adjust it to open and close with a minimum of effort.
One thing that always frustrates me when mounting a scope is the movable base jaws that flop around and force you to hold the rifle is odd positions to keep the jaws open. These rings has captive screws that force the jaws apart at all times whenever the cam lever is loose. That will take scope mounting from a three-hand operation and make it suitable for just two.
That little coil spring acts like a third hand to hold the scope base jaws apart during mounting.
This picture is for Matt61, who said he doesn’t understand what cam-action means. This picture should explain it.
Mounted on the Diana 350 Feuerkraft, the Leapers UTG Quick-Detach rings look and work very well.
How does it work?
Well, that’s what caught Mac’s attention. These mounts/rings work just as nice as they look. If you have several rifles that must share a scope, or if you’re like me and are always testing new guns, they’re a real blessing.
These ring sets come in both one-inch band 30mm diameter and low, medium and high heights. They fit a wide body of applications. And, being two-piece rings, they’re far more flexible that one-piece.
More and more airgun manufacturers are seeing the utility of fixing Weaver bases to their guns, so these mounts will have an ever-increasing value. I see the day coming when Weaver bases will be the standard, and few guns will be made without them. Then, you’ll want to own a couple sets of these in each size.
I don’t have any of these yet but I sure do like the looks of them. I put them on my wishlist. I have the 11mm to Weaver adapter there too but at $42 they’re not near the top.
-Chuck
Very nice! This is a good way to not only share a scope across rifles, but also for carrying two rifles in the same case, with a single scope, mounted, or unmounted. I have one case with two rifles, and the tip of each barrel was always scratching the under-side of the others stock. I now have black duct tape where the scratches are to prevent further damage.
Victor
B.B.
A very interesting solution, very useful for testing.
Just two questions:
How do you feel about the consistency of its grip?
What’s your estimation for rings’ service life? Cam-locks are known to be very demanding on material, first of all friction resistance, lots of swapping may wear locks down.
duskwight
duskwight,
All good questions. All bearing surfaces are steel on steel, so it should last. And it is adjustable, as mentioned in the report.
B.B.
BB / duskwight
The camlocks are very similar to the ones used to hold the wheels onto average to high-end bicycles. They take an ungodly amount of abuse on the road and trail (rain,mud,crashes), get removed and reinstalled several times a day, and last for years. I can’t see these Leapers versions wearing out in th owner’s lifetime.
Well, I guess that’s all fine and dandy if you do a lot of testing with different rifles that have Weaver rails.
Let’s see now…
3 scopes, each mounted in a set of rings of different heights so that one should fit any rifle fairly well. That should make things handy when dealing with Weaver rails.
Swapping between two different rifles back and forth all the time would require zeroing each time anyway, so I don’t see that you would gain much there. Better to just set up both rifles with scopes in the first place and leave them there.
What about repeatability? Can the scope be repeatedly removed and installed on the same rifle without the need to zero again? How much error could be expected?
twotalon
The ability to maintain zero would be my big concern. Some of the rings out there that can hold zero after being removed and remounted often run $100 to $200, if these will they would be real bargains. Have you done any testing on this matter?
Bub
Not me.
I have a feeling that it would vary with each individual set of rings. Repeatability could also vary at different temperatures. How far apart the rings are could make a lot of difference. Logic dictates that the farther apart the rings are, the more repeatability there should be.
I would rather not bother with the whole issue in the first place. Just slap it on, zero it, and leave it.
twotalon
Bub,
No, we haven’t tested zero retention while removing and installing the rings. Maybe that’s something Mac might do in a Part 2?
B.B.
I have two sets of these and I can tell you that they “do not hold zero” 🙁
Nonetheless they are a very nice set of rings. Once on the gun they will not move.
Munchie,
Are the rings at fault or the scope? If the rings don’t move, how can they be the problem? I don’t understand.
B.B.
twotalon,
Of course a test would have to be conducted, but Mac did remove and re-install them and they did return to zero.
B.B.
Yes, this is my big question about the rings with Jason Bourne in the back of my mind. How do the rings hold zero when you move the scope? A test with before and after photos would be interesting.
Matt61
They look good. However, I don’t see a 1 inch version. There are a lot more scopes out there with 1 inch tubes than 30mm. Perhaps those are on the way?
Mike
Mike,
There are several one-inch ring sets to choose from:
/product/1-quick-detach-rings-high-weaver-picatinny-see-thru-law-enforcement?a=3471
Did you search among the Weaver base rings?
B.B.
Here are all of the 1-inch rings — so far. If I’m not mistaken, additional quick-detach mounts will soon be available from Leapers/UTG:
/product/1-quick-detach-rings-medium-weaver-picatinny-see-thru-law-enforcement?a=3470
/product/1-quick-detach-rings-high-weaver-picatinny-see-thru-law-enforcement?a=3471
/product/utg-1-max-strength-quick-detach-rings-medium-weaver-picatinny-see-thru?a=3495
Edith
Thanks BB, I did a search for them from the main menu under “accessories”. The one inch versions didn’t come up. Thanks!
Mike
I just ran the search again, it worked this time.
Mike
too bad they won’t work on dovetails. I find zeroing a scope to be the least amount of work and time – dealing with 4 or more screws when changing scopes and/or rings is my big headache.
Fred PRoNJ
Fred PRoNJ,
You just need one of these:
/product/utg-11mm-to-weaver-adapter-vertical-scope-stop-pin?a=2401
or this that is adjustable so can swap the scope and rings from gun to gun and be close to or on zero:
/product/b-square-17021-11mm-to-weaver-adapter-adjustable?a=601
and more options:
/product/bkl-2-pc-3-8-or-11mm-dovetail-to-weaver-adapter-1-long-matte-black?a=2922
/product/bkl-3-8-or-11mm-dovetail-to-weaver-adapter-4-long-for-bolt-action-guns?a=2921
/product/bkl-3-8-or-11mm-dovetail-to-weaver-adapter-4-long-matte-black?a=2923
kevin
Hi Kevin,
very busy here at work plus I’m celebrating 25 years of wedded bliss. Anyway, the idea is to buy only one device. Why should I need to purchase an adapter inorder to use a Picatinny/Weaver mount? But, we work with what is available.
Fred PRoNJ
Fred,
Re: “Why should I need to purchase an adapter inorder to use a Picatinny/Weaver mount? ”
IF you have multiple guns with dovetails that you want to scope, the reason to buy inexpensive dovetail to picatinny/weaver adapters and one set of quick release rings (like in todays article) is so you only have to buy one nice scope. Why have 4 crappy scopes when one nice one would do?
kevin
Kevin,
if the majority of my rifles have dovetails, and that is the case, I’d rather forego purchasing the Weaver/Picatinny rail adapter and quick detach rings and just be able to purchase a few sets of these quick detach rings that would be able to directly mount onto the rifles’ dovetails. I don’t disagree with your reasoning, just questioning why not also offer the rings for dovetail mounting as well?
Fred PRoNJ
Fred,
11mm dovetail rings that are quick-detach are probably coming soon.
Edith
I’LL TAKE 3 (and be glad to test them as well)!
Fred PRoNJ
Yay!!!! One of those, “Why didn’t they think of that sooner?” things.
-Chuck
Edith, I forgot the best defense of all against someone hiding in the back seat of your car: look there before getting in. The same goes for navigating dark spaces like parking lots. (I had not realized but should have that the hours you were keeping with Tom in the hospital would have had you out pretty late.) For the dark places, you want to scope things out in advance and take corners wide which is an old samurai tactic to avoid ambush. I’ve heard different things about keys. They can do damage to an assailant but also to yourself with their jagged edges if they aren’t held right. Holding them inside of a closed fist with some length of the key protruding is one way about which I’ve heard different opinions. I prefer another way recommended by a guy who goes by the names of Jim Grover of Kelly McCann who has a lot of good ideas. You hold the key in the same grip as a toothbrush with just the tip protruding past your thumb. That way you hold it steady and the assailant will not be able to see it. Then you make s-shaped defensive motions while backing away–or in whatever situation where you find yourself. If the assailant does make a grab from the backseat or from behind in any location, it is all important to keep the chin down to protect the windpipe and buy you time for whatever else you do. Hm, maybe this is not making you feel better…
Herb, as for the semantics of “call radius”, I just borrowed that term from David Tubb without thinking much about it. Now that I do I don’t know if I see a big problem. This is actually a teachable moment to reflect on just what it means to “call” one’s shots. I interpret this to mean having control of your shot process enough so that in the instant that the shot discharges, you will be able to tell with a good degree of accuracy just where your shot will land. So, the key element of “calling” refers to conscious control. Calling a shot as a flier is just one outcome. You could just as well correctly call an X. So a “call radius” would be the radius within which you can consciously hold your shots with certainty. For Victor, this would be the 10 ring, for most other people, it would have a larger radius. In principle, the concept seems legitimate even if it’s not easy to pin down exactly what it is. Barring some outside intervention, I’m sure that I have a call radius at a 100 yards rested that is somewhere between a barn door and a pin head. And the concept seems useful for, among other things, comparing my human capabilities with that of a given rifle which will print out some group size from a vice. If the semantics of “call radius” are bothersome, what would be a better term for one’s group size within which one can hold their shots reliably in the absence of an outside distraction?
Victor, thanks for the tip on “affine.” I remember reading about affine transformations but the concept didn’t stick….
Mike, thanks for the info about the No. 4 Mk I. I’ve read extensively and all the info says that the aperture battle sight is zeroed for 300 yards and the flip-up ladder sight for between 200 and 1300 yards in 50 yard increments. Argh! I won’t be shooting at 1300 yards. Very good news that you can adjust down to 100 yards. I’m waiting for B.B. to weigh in on this since he said that he enjoys shooting his .303 at short range which for me means under 200 yards… I understand that the British sights are not adjustable for windage, but that’s okay. All of this gives me a renewed appreciation for the M1 Garand sights which are adjustable for 1 MOA for both elevation and windage. Yet, another reason why it is the greatest battle implement. I am impressed by your 3 shot 100 yard cloverleaf. IMR 4064 all the way. That’s what I will be loading with. My best with the Garand is your group at 50 yards with Greek surplus and my super-tuned rifle from Clint Fowler.
I got my replacement IZH 61 buttstock last night. It is definitely stiffer than the old one which was suffering some fatigue, but the main problem is clearly the mainspring, so we’ll get that replaced.
Matt61
Matt,
RE: Call radius
Your definition is consistent and complete so there is longer any semantic ambiguity.
When I did chemical analysis, I would typically use multiple samples. If a mistake was made in the analysis it would be noted and if the result was seemly low or high, it would be discarded due to the assignable cause noted.
To me a “flyer” would be a shot with an abnormally large deviation but for which there was no known cause. The assumption in shooting pellets would be that there was some undetected problem with the pellet.
Regards,
Herb
Matt61,
What you’re saying about “calling” shots is exactly right, and also what I wrote about yesterday. In practice, we should be able to call our shots, good, or bad. In the case of shooting for groups, if the shooter didn’t feel good about a shot, and it turns out that the shot was in fact bad, then in a 10 shot group, the bad shot should not be counted. Remember, we’re somewhat trying to take the shooter out of the picture as much as possible. If someone is doing accuracy with a springer, it’s not that hard to blow a shot or two in a 10 shot string. We’re more interested in how well the rifle can do, and not the shooters ability, or mental endurance, throughout a 10 shot group. Fortunately, B.B., and Mac, are able to shoot good 10 shot strings, but on occasion let us know that THEY were the cause of a flier. Again, if I see a 10 shout group, with only 1 or 2 shots that are significantly off, I will look at the 9 or 8 shots that were in the tight group, and ignore the 1 or 2 that are not. Springer’s are hard enough to shoot that it’s not very difficult to blow a shot.
Again, whole point of B.B.’s accurate test was to demonstrate improvements when doing certain things, like cleaning pellets, oiling pellets, or both. I think that the majority of the shots within two, or more, groups will tell us what we need to know.
Victor
victor,
In my opinion, your way of identifying fliers, as described in your above comment, is a good one that I think we should implement. It takes into consideration both the shooter’s random stability and the pellets fickle nature as well as the effects of Mother Nature.
I also believe the follwing quote from BB’s previous reply sums up the whole exercise and eliminates the need for a slide rule:
QUOTE … We aren’t looking for the most accurate airguns in this series. We are looking for ways to make any airgun more accurate. That’s what this series is about.
The starting point makes little difference, as long as the finishing point provides better accuracy. The type of gun that took us there is more or less irrelevant.
END QUOTE
-Chuck
Chuck,
Agreed. Furthermore, the choice of 25 yards, versus something like 10 yards, eliminates the necessisity for ultra fine measurements, and the devices needed to make them. Whatever gun, or pellet, is tested, the error will be easily measurable, even by inspection. Also, B.B. has chosen a good rifle, and not a super precise one. This, I think, helps to make these test’s more “real world” in that, we should be able to see if a “good group” becomes a “better group”, or a “worse group”. With too precise a rifle, it would be hard to see as much improvement. With too inprecise a rifle, it might be hard to seen either improvement or decline. I think that B.B. defined the parameters about right, as might be expected. He’s got better experience with this kind of thing than most of us.
Victor
Your M-1 should be great as tuned. The one I have has a match grade trigger group and a National Match front sight. Other than that, it’s “GI”. As to the No 4 Mk I, even if you can only get a 200 yard zero, you will only be a couple inches high at 100 yds. But, my experience says you will do better.
Sources have said that the Enfield is the best bolt action battle rifle. I would agree.
Mike
Mike, I’m quite interested in a comparison of the 98 Mauser with the Lee Enfield. The Mauser, I think, is acknowledged to be the ultimate bolt-action design in terms of strength and general superiority. When the Mauser encountered the Lee-Enfield in the Boer War, the Mauser did so well that the British were thinking of copying it, but were not able to before WWI intervened. But in France, it was the Lee-Enfield that showed to advantage in encounters with the Mauser. Why the radical difference? I suspect it was the environment. The Boers used their Mausers at longer range whereas distances in trench warfare were much shorter which favored the higher rate of fire of the Lee-Enfield. Besides, the Boers might have just been individually superior shots to the British line troops.
What is attracting me to the Lee-Enfield is the super slick, smooth bolt-action; great reliability (apparently the Lee-Enfield is one of the few designs that can feed empty cases); and accuracy that is comparable to other bolt-action designs. Besides, we know from the Air Arms products that the British know how to make guns.
As for the Arsenal AK, my impression is that the 7.62X39 model is a 2.5 MOA rifle and the 5.45 version is sub-2MOA; I’m supposing this is with a scope. That sounds comparable to a stock Lee-Enfield without accurizing.
Matt61
Matt61, I would say that your analysis of the Enfield vs Mauser is correct. The Mauser is generally more accurate but the Enfield is a 10 shot firearm and better in WW 1 conditions, LOTS of mud.
I also agree that the Boers were better shots on the average. It has been said that the Germans had the best hunting rifle, the Americans had the best target rifle (1903) and the British had the best battle rifle. I have a 1898 Mauser with a 29 inch barrel in 7X57 caliber. It is very accurate. The Mauser did impress the British. They were going to go to that design until WW 1 got in the way. That rifle was the Number 3, the Pattern of 1914. It was also to have a high powered 7mm round as well. Of course, we used it too. It became the 1917 “Enfield” in .30-06.
Mike
Matt61, another point I should mention about the loads I use in the Enfield. I use 150 grain bullets. That also makes it easier to get a 100 yard zero. With 150’s, you have less “barrel time” than with the military 175 grain bullet hence less barrel rise prior to the bullet leaving the barrel. So, the impact will be lower at a give sight setting.
Mike
When buying an Enfield, look for an early war version or a post war version (WW II). Mid War, the Brits took shortcuts to produce more rifles. This was not for the best and was regretted. However, Mid War rifles that have been FTR after the war may be OK. Post war No. 4 Mark II’s are excellent. Some were never issued! I have had two of those but I let one get away. My bad!
Mike
I’ve kept to the sidelines with the discussion of what is meant by accuracy but now I’ll weigh in with my 2 cents. To me, and I’ve already had a blog published on what is accuracy, is how small a group a paritcular rifle is capable of. I’m talking about a rifle action and barrel that can take a pellet and put it right where the point of aim is every time. Herb and others have talked about fliers and it’s taken a number of years of shooting for me to feel confident that when a pellet falls outside of my POA, it’s the pellet’s fault and not mine. I agree that these fliers should not be taken into account in the determination of the accuracy of a rifle as one must agree that this flier is the pellets’s fault or the shooter’s fault and not the rifle’s fault/ How many times have we all shot pellet after pellet with a single rifle and achieved results that resembled a shotgun spread and then, voila (Vi=ola to you non-sophisticates), we stumble upon a pellet that groups! Bottom line, what is the group size and this should be the determining factor for accuracy.
There, I think I said what I wanted to say and now I’m going back to the land of NOD. One more day till the weekend!!!
Fred PRoNJ
Fred PRoNJ
Here’s my take. Tiny groups equate to precision. Tiny groups at POA equate to accuracy.
Of course, this means that accuracy is a function of the gun’s sights and how they are used by the shooter, not the gun itself. It also means that precision is necessary if accuracy is ever to be achieved, that is to say you can’t be accurate without also being precise but you CAN be precise without being accurate.
Let’s take BB’s testing for example. He intentionally shoots off of POA to preserve it. A casual observer might look at his groups and think,” why, thats not very accurate.” And they would be right! But the groups DO show precision (when the rifle and BB are doing their part 😛 ) Accuracy would follow if BB correctly adjusted the sights.
PS: I didn’t even realize you were a fellow sophisticate! Have you received your copy of ‘Wine & Cheese’ magazine this month? Mine’s not arrived. Perhaps the butler misplaced it.
Slinging Lead – I’d of course agree that a rile shooting 10 inch groups at 10 yards is as close to useless as a rifle could get. But I think you’ve missed the point completely about the difference between the terms accuracy and precision.
Believe me, I’m much better with statistics than a rifle. There is an old saw that to a statistician with one foot in the fire and the other on a block of ice is “on average” comfortable.
If shots are dispersed around the POA so that the average POI coincides with the POA, then (according to the statistical definition) the shots are “accurate.” In other words, the sights are adjusted as well as they can be. Thus the statistical definition of accuracy does not depend on the dispersion of the shots at all. So shooting can be accurate but imprecise. (An accurate but very imprecise rifle would of course be better used as a club!)
The statistical term precision is a measure of the dispersion of the shots around the average POI. So the smaller the group size, the more precise the shooting.
In shooting articles it is typical for accuracy to be used as synonymous with precision. I’m sure that I’ve done it too. However the language of performance measurements is mathematics, and the most applicable discipline within mathematics is statistics. There just isn’t any reason to continue to use sloppy terminology for well defined concepts. The deeper the discussion about statistics the more important to use use good terminology.
Regards,
Herb
Herb
There is the off chance that you might be seeing this discussion too much through a statisticians prism. You might not think so, but that is where subjectivity meets objectivity.
Words in common use can have different meanings when considered in different professional circles. For instance the term “mixed liquor” when used by barkeepers means something vastly different than when used by wastewater treatment plant lab analysts.
You may have proven my point for me. A rifle that shoots two feet from the POA in opposite directions is just not accurate. According to a statistician it might be, but not for anybody else.
I would readily admit I have used sloppy terminology in the past, but not in this case. I think I am using the definitions correctly as they are understood in general terms not statistical ones. But then, my opinion might not be statistically significant!
Slinging Lead –
I do understand that I’m out on a limb on this. I would totally agree that in most forum posts and articles about shooting tend to use accuracy as synonymous with what is defined as precision in statistics. I know that I won’t be able to win this argument. But I think I’ve made my point that there are two different concepts here.
I thought that it was important to beat the drum on this is because it is impossible to analyze the performance of a rifle without using statistics. So I do think that there is a significant and pertinent overlap.
Regards,
Herb
PS – I always heard that you don’t buy beer but rent it. Your reference to “mixed liquors” adds another whole dimension to the concept of a boilermaker. 😉
Herb
That is so weird, that has got to be my favorite phrase in the world, “…but rent it.”
Best regards, and no hard feelings of course. You are an intimidating guy to lock horns with!
Fred PRoNJ,
No kidding! Pellets have a personality all their own. Crosman Wadcutters form random shotgun patters in guns that I’ve tried them in (not super wide, but definitely not tight). H&N form consistently nice tight groups. Daisy wadcutters can group tighter than most pellets, but then also have the wildest fliers (they are cheap, and of known poor quality, BUT they are also pure lead, which I think helps with accuracy).
Victor
They look very similar to a quick release on a bike seat post or wheel except for scopes.
Robert from Arcade,
You wrote this comment on another one of our blog postings. It’s about your BSA Supersport in .25 caliber. I was particularly interested in the following statement:
“front sight is not a fiber optic blob, and it is reversable”
I emailed Pyramyd Air’s tech department because I didn’t see how it could be reversible. They don’t have any .25 cal. guns in stock now, but they checked the .177 caliber front sight and it’s not reversible. However, it IS removable. Is that what you meant to say? If not, and you really do have a reversible front sight, please email an image to me at edith@pyramydair.com.
Does your front sight look like the one in the detail shot shown on the page below:
/product/bsa-supersport-air-rifle?m=2461
Thanks,
Edith
AMENDED REPLY TO POST FROM 2 DAYS AGO, Re different rifling types in barrels:
Herb, BG_Farmer & Slinging Lead,
Sorry, my computer crashed and I’m only now catching up. BG- yes, gain twist was one of those I was referring to- couldn’t remember the name. Herb, you were actually the guy I was thinking of as I was writing the question and couldn’t remember your name either- it’s been so long since you last posted. I knew my “theories” were not very solid, and you raise a very interesting additional consideration- that the intended range affects (or should affect) your choice of twist rate. Your implication was, if I understood you correctly, that for longer ranges you would favor a slower rate of rotation?
AlanL
Alan,
Yes, it seems that long range shooting may benefit from a slower twist. There is a poster on the yellow named Harry who uses the name Yraah who has been doing a lot of careful experimenting with long range shooting. Very nice gentleman who is very knowledgeable and a very solid poster.
The notion of “cone of fire” denotes a geometric extrapolation which doesn’t seem to hold at long ranges. According to the notion of a cone of fire, if I had a 1/2 group at 50 yards, then I’d have about 1 group at 100 yards and 1.5 inches group at 150 yards. Harry’s experiments, not just theories, indicate that this would be true for some distance, but that then precision gets worse at an increasing rate. (Note at long distances the spin doesn’t slow as fast as the forward velocity.)
Harry’s theory is that the drag stabilization at the lower velocity decreases to the point that the spin can cause the nose to angle away from the ballistic path. That in turns causes the pellet to precess, then further downrange to corkscrew. A full mathematical model has not been formulated, but it makes sense to me.
Regards,
Herb
That makes sense to me as well. Why would we expect perfect linear degradation throughout the trajectory. The longer the projectile is in flight, the further away from ideal characteristics it gets, which I would expect to degrade at an accelerated rate.
Victor
Herb,
I remember arguing with you about this a couple of years ago :). I still think the drag stabilization and spin-stabilization of a pellet are working at odds to each other, and that that is what causes the precession/spiralling. Spin stabilization tends toward a constant angle (parallel to the line of the bore), while drag stabilization forces an angle tangential to the trajectory. I believe very slow rotation enough to average out irregularities in the pellet but not enough to spin-stabilize are the way to go as long as we retain drag stabilization as the main mechanism in a pellet. The twist rates in most pellet rifles are too fast — more or less the same as for .22 rifles, which means that the faster the pellet goes, the more likely spin-stabilization is liable to become a problem counteracting the drag stabilization.
For what its worth, I agree that the geometric cone of fire is fairly untenable — dispersion seems to follow a power (of 2? in many cases), i.e., 1 inch at 50 yards, 2 at 100, 4 at 200.
BG_Farmer;
We probably did discuss this in the past. It has been a point of great curiosity for me since my hunting as a kid was with a shotgun. You don’t really aim a shotgun as much as you point it of course. It has been a really adventure in trying to learn how to shoot a rifle well.
For the most part I think we’re having a “violent agreement.” I’d also stipulate that the concepts have matured in my mind after many fruitful discussions on the web.
Out of a smooth bore, round balls won’t shoot as well as diabolo pellets because the diabolo pellets are drag stabilized as well. A rifled barrel will, in general, however shoot diabolo pellets better at 10 yards than a non-rifled barrel. So all spinning isn’t all bad as you point out.
I don’t think that spinning and drag-stabilization are at cross-purposes. Rather I think that spinning has two different factors which are opposed to each other relative to precision in shooting.
First spinning does average out say a rotational weight imbalance. The faster you rotate, the better the weight variation is averaged out. You do reach a point where the spin rate is so great that the pellet will disintegrate. But normal rotational rates are nowhere near this velocity.
The second problem is that the spinning causes a yaw – an angle between the ballistic path and the geometric center-line of the pellet. The greater the spin, the greater the yaw angle. Of course if you were shooting in a vacuum, then the yaw angle would not be a problem. But in air the yaw angle causes the pellet to curve. Also in air a yaw angle increases aerodynamic drag and hence lowers the ballistic coefficient.
So you’re left trying to spin the pellet fast enough to average out weight variations, but not so fast as to cause a large yaw angle.
To continue to develop this model, consider a “two-armed” model of how the pellet spins around its center-line. The larger arm would be precession and the smaller arm nutation.
The relative rates of precession and nutation I think are dependent on whether the discussion is about a bullet or a drag-stabilized projectile.
There is the yaw angle which is the “time averaged” angle between the ballistic path and the center-line of the pellet.
The pellet can also spiral – that is travel in a helical path greater than the diameter of the pellet. The greater the yaw angle, the more likely this will occur. It really seems that all pellets would eventually spiral, it is just if we can track them far enough. Thus spiraling denotes a peculiar instability that drag-stabilized projectiles can have which bullets cannot have.
Regards,
Herb
BB,
I’m looking to upgrade my scope. Currently I have a Centerpoint 3-9x40AO that came with a sheridan super steak (i believe it was called) several years ago. These days it sits on my AA 410, I think it is a pretty nice scope and it serves me quite well but then again, i don’t have an awful lot experience with them. (guess I can be talked out of upgrading…).
Anyway, what I would like to get out of an upgrade is: stronger magnification and better clarity. I have been looking at the leapers scopes since they have a reputation of being great value. Particularly the
Leapers Accushot 4-16x56AO which looks like a nice scope but it comes with an illuminated mil-dot reticle. My previous experience with an illuminated reticle hasn’t been overwhelming, also it seems that there are no mil-dots on this scope when the illumination is not used…
I’m just wondering how much of the price of this scope is connected to the illumination of the reticle an if there might be a scope with similar features without the illumination that has a lower price tag or a scope with vise versa…
Thanks as always,
Jacob V.
Jacob,
Take a look at the Hawke line. They are incredibly clear and sharp.
B.B.
Jacob V.,
A 56mm objective means very high rings and very high rings challenge a good cheek weld. If you get a scope with good glass you don’t need a huge objective. There are some great scopes in the hawke lineup. The bushnell 3200 and 4200 series have 40mm objectives, are very lightweight (why add unnecessary additional weight to a great, lightweight rifle like the S410?) and have dropped dramatically in price since the speculation is that they will be dropping this series in favor of a new and better (don’t know how they can be better for the pricepoint??!!) series.
If you haven’t looked through a bushnell 3200 or 4200 do yourself a favor and visit your local sporting goods dealer. Yes they come in mil dots, yes they have AO, yes they focus down to 10 yards, yes they’re lightweight and they have great multi-coated glass. Go look through one.
kevin
Jacob,
Take a look at the Hawke line. They are incredibly clear and sharp.
B.B.
To avoid dozens of small posts I’m going to break the threading chain somewhat… Besides, most of the following is more on the order of snarky observations.
BG_Farmer
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For what its worth, I agree that the geometric cone of fire is fairly untenable — dispersion seems to follow a power (of 2? in many cases), i.e., 1 inch at 50 yards, 2 at 100, 4 at 200.
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That still looks linear… Double the range, double the dispersion. If, instead, you’d said “4 at 150” it would show growth, but as is, one can infer “3 at 150” which gives a simple formula of
1*(range/50)
java
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sheridan super steak
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Sounds like a painful dinner (Couldn’t resist… Suspect you meant “Streak” rather than “Steak”… Given how many brands are now in the hands of Crosman it becomes confusing; Pyramyd catalog shows a Benjamin Super Streak and a Sheridan Blue Streak)
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Leapers Accushot 4-16×56AO which looks like a nice scope but it comes with an illuminated mil-dot reticle. My previous experience with an illuminated reticle hasn’t been overwhelming, also it seems that there are no mil-dots on this scope when the illumination is not used…
“””
The dots remain; they’re etched into the reticle surface. What may be misleading is, as I recall, when illumination is ON, only the central part with the dots “glows” — the main “duplex” arms remain dark.
Slinging Lead
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For instance the term “mixed liquor” when used by barkeepers means something vastly different than when used by wastewater treatment plant lab analysts.
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Unless processed through a drunkard and spewed down the drain