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At what range were these targets shot? As an artilleryman, I see these results a bit differently. We artillerymen think of dispersion in terms of "CEP" - circular error of probability. The artllery CEP is a circle flat on the ground, and the statistic is the number of rounds that land inside the circle vs. the ones that land outside. So "CEP" takes into account, and combines, range probable error and lateral dispersion. The rifle targets above are akin to CEP targets, only vertical instead of horizontal.

What is significant to me is the number of hits within the "CEP" circle compared with the hits outside of it. That perspective makes the "JG11" still look pretty good.
Apologies, I have forgotten to mention the range, which is 300m.

It seems pretty straightforward here. The distance is known, 300m. The only thing theoretically tested here is the mechanical dispersion of the firearm + ammunition.

What I don't understand is the fact that you write "the number of hits within the CEP circle". By definition, if I understood it correctly, the very definition of the "CEP circle" is the radius formed by the impacts of 50% of the rounds shot, on target. Since both targets have 25 rounds on them (as specified), the number of shots inside this "CEP circle" is the same... no?

Therefore, what matters is the size of that radius. The Kar. 31's is tighter, the Ig. 11's is looser, as shown on the results above.

Back to square one. Why is there a preference on the Ig. 11 over the Kar. 31 "all things being equal", when you have the historical data as presented above clearly showing the opposite?
 

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All things being equal means each rifle is in an original issued condition whith an unchanged stock, ... Fired without sling pressure and no stock pressure working problems at all.
All things are not equal when you enter the human equation and add the sling.
My "history" is based on pure rifle performance alone in a firing device, nothing else.
So, what do I follow? History or factual very long term experience with both being fired as I described. For me, it's a pointless argument and requires no more comments from me.

And in case you missed the premise for all of this.......... It had nothing to do with competition. It only had to do with load data gathering and load data proofing, nothing else. Once a load did prove itself, it was logged in and then only after 10 rounds on 20 targets with complete repeatability.
 
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Apologies, I have forgotten to mention the range, which is 300m.

It seems pretty straightforward here. The distance is known, 300m. The only thing theoretically tested here is the mechanical dispersion of the firearm + ammunition.

What I don't understand is the fact that you write "the number of hits within the CEP circle". By definition, if I understood it correctly, the very definition of the "CEP circle" is the radius formed by the impacts of 50% of the rounds shot, on target. Since both targets have 25 rounds on them (as specified), the number of shots inside this "CEP circle" is the same... no?

Therefore, what matters is the size of that radius. The Kar. 31's is tighter, the Ig. 11's is looser, as shown on the results above.

Back to square one. Why is there a preference on the Ig. 11 over the Kar. 31 "all things being equal", when you have the historical data as presented above clearly showing the opposite?
It is important to know the range, since CEP will vary over the entire spread between minimum and maximum range. Note that artillery is subject to minimum range considerations, mainly due to fuse arming.

The two pictures you posted above probably reflect different ammunition lots, or possibly rifles with different degrees of bore wear. It is not specified, so we have to guess.

As you point out, the CEP is determined by the fall of shot of 50% of the rounds fired. That is reflected in the "Streuungsradius 50%" data. From here on I will use the CEP diameter - i.e. double the radius, for a clearer mental image. The "middle" data shows the K31 50% hits inside a 7.6 cm/3" circle, or MOA, compared with the "JG11" with 11 cm/4 7/8". The 100% - all hits - circles are 16.4 cm/6 1/2" for K31 and almost twice that for the "JG11. The "good" data shows 7 cm/2 13/16" for the K31's 50% hits and 9 cm/3 5/8" for the "JG11"; the 100 % hit circles are 14.6 cm/5 13/16" for the K31 and 23 cm/9 1/8" for the "JG11."

Absent any explanation for this rather wide spread, I would guess differences either in ammunition lots or rifles with different degrees of bore wear. But another factor to consider is the effect of the machine rest. This introduces another variable,and it could be very significant.
 

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It is important to know the range, since CEP will vary over the entire spread between minimum and maximum range. Note that artillery is subject to minimum range considerations, mainly due to fuse arming.

The two pictures you posted above probably reflect different ammunition lots, or possibly rifles with different degrees of bore wear. It is not specified, so we have to guess.

As you point out, the CEP is determined by the fall of shot of 50% of the rounds fired. That is reflected in the "Streuungsradius 50%" data. From here on I will use the CEP diameter - i.e. double the radius, for a clearer mental image. The "middle" data shows the K31 50% hits inside a 7.6 cm/3" circle, or MOA, compared with the "JG11" with 11 cm/4 7/8". The 100% - all hits - circles are 16.4 cm/6 1/2" for K31 and almost twice that for the "JG11. The "good" data shows 7 cm/2 13/16" for the K31's 50% hits and 9 cm/3 5/8" for the "JG11"; the 100 % hit circles are 14.6 cm/5 13/16" for the K31 and 23 cm/9 1/8" for the "JG11."

Absent any explanation for this rather wide spread, I would guess differences either in ammunition lots or rifles with different degrees of bore wear. But another factor to consider is the effect of the machine rest. This introduces another variable,and it could be very significant.
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The reports I have shown are done in the early 30s as a demonstration of the Kar. 31's capabilities compared to the Ig. 11's. Here are a couple more from the Federal Archives, E5210-01#1999/23#106*. You can also download the report showing the target comparisons, here as an attachement

Therefore, based on what I am seeing in these historical documents, the Ig. 11 is inferior to the Kar. 31 in terms of mechanical dispersion (aka. "all else being equal", same ammo, same machine vice, same distance, same testing conditions... etc etc).

This is to be expected, as the Kar. 31 has superior stock bedding and geometry, a stiffer barrel, better barrel attachment to the receiver and a more rigid action.

However, one may argue that the Ig. 11 may be more "practically precise" due to its longer sight radius and lower recoil linked to the higher weight (less flinching). In this case, the "all else being equal" principle no longer applies.

So to respond to the original author's request on "what rifle is better"? I guess you need to try both and decide, or even better, buy both!
 

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The "Beurteilung" : "Karabiner 29 gibt somit selbst auf 1200 m sowohl 50 %ige als auch 100%ige bessere Praezision als das Langgewehr."* is pretty conclusive. But bear in mind the ammunition at that time had mercuric priming, so comparison with post 1950 GP11 is a bit tenuous.

Also of interest is the observation of the effects of a hot barrel: better at 600 meters but worse at 1200.

*Karabiner 29 yields at 1200 meters both 50% and 100% (i.e. CEP and beyond) better precision than the long rifle i.e. M1911.
 

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For some perspective, we must remember that the aforementioned tests of the K31 (then known as K29) are system tests, i.e. rifle and a standardized round - GP11. When Latigo describes his results, these are with loads that have been carefully developed and tailored to perform with the Langgewehr. Factoring in bullet mass and ballistic coefficient, rifling twist rate, powder burn rate - pressure gradient - and the subtleties of barrel harmonics and bedding, it is not difficult to accept both findings as equally valid within their respective contexts.
 

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My sincere apologies to both Leon and Meerkoos. For some reason I had not considered a very obvious difference until Leon's last response. Out of some 1,700 log-ins with recorded load data over some 40+ years, not a single one of them involved GP11. I can't believe I let that slip by without noticing it, however that both of us in entirely separate categories as pertains to both of those rifles.
P
 

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P, Latigo: let's press this thread to its most beneficial outcome. What is the SP non-plus-ultra load for the Langgewehr?
I think at this point it is very apparent that one shoe - GP11 - does not fit all feet as well as it does the K31.

I would like to explore the optimum load for my K11. Granted, its shorter barrel (than the K31's) is a drawback, and arguably its rearward locking lugs are also a detriment, I still like this rifle and get the most enjoyment shooting it. Well, I have to qualify that: my two K31's in after-market stocks are a pleasure to shoot too.
 

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Latigo, Leon, et al... very good info. I always suspected the G1911 was every bit as capable of superb shooting as the K31, but your comments (and empirical observations) are good to know.
 

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As Albert Einstein, a one-time Swiss patent office clerk observed, repeating an experiment and expecting a different outcome is the definition of insanity. Since there is no pre-1950 GP 11 available, it is not possible to confirm the K29 vs. M1911 shoot-out results. Prior to 1950 or thereabouts, GP11 had mercuric primers. Mercuric primers are not corrosive, but they deteriorate over time in storage. Corrosive primers, on the other hand, are stable and can be stored almost indefinitely in a proper environment. As every precision reloader knows, primers make a difference.
 

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Hi Leon. I'll see if I can address this sometime tomorrow, I can tell you that very early on I ruled out the K11 as being useful for load data gathering. They just didn't seem to hold a group as well as either of the other two.
In the early days I was using .284 win and Norma brass, sometime in the early 60's and 70s that was I believe, and I bought a lot of ammunition from Mandel's in Arizona when they showed up, and I think that was in the old shotgun news.
Talking about something like this makes me realize how quickly time is slipping away, Leon. Load data gathering in those early days was a lot of fun because it was still wide open with not much written about our caliber.
I do remember that a lot of the load data gathering as pertains to the G 11 was done with .284 Winchester, but I can't remember for sure without looking at all of now.
Interesting thread anyway.
P
 
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Hi Leon. I'll see if I can address this sometime tomorrow, I can tell you that very early on I ruled out the K11 as being useful for load data gathering. They just didn't seem to hold a group as well as either of the other two.
In the early days I was using .284 win and Norma brass, sometime in the early 60's and 70s that was I believe, and I bought a lot of ammunition from Mandel's in Arizona when they showed up, and I think that was in the old shotgun news.
Talking about something like this makes me realize how quickly time is slipping away, Leon. Load data gathering in those early days was a lot of fun because it was still wide open with not much written about our caliber.
I do remember that a lot of the load data gathering as pertains to the G 11 was done with .284 Winchester, but I can't remember for sure without looking at all of now.
Interesting thread anyway.
P
This thread has digressed from the original question, but has, I think, become even more interesting and relevant to those of us shooting and reloading for the Langgewehr, K11 and K31.

I used the term "system" because the rifles in question must be evaluated in the context of the ammunition used.
GP11 was designed for the long rifle. It was used with the shorter K11 because it was the standard service round. Understandably, the K11 was expected to shoot the same ammunition used in the longer rifle and the higher MV achieved with the extra 7"-8" of barrel. Then came the K31, with a different chamber. As Meerkoos has documented, the K31 performed better with the GP11 ammunition designed for the Langgewehr and its longer barrel. Colonel Furrer managed to optimize performance of GP11 in a shorter barrel. Let us not overlook this bravura ballistic engineering!

So the question arises: can the 7.5x55 be tailored to optimize performance of the K11? "P" has already shown what can be down with tailored loads for the Langgewehr and K31. I don't think the K11 should be dismissed owing to its short barrel. Why bother with the K11? Well, this shooter's old eyes do better with the K11's rear sight located 4"/10 cm further away from the shooter's eye than the K31's.

So, does anyone else that enjoys shooting the K11 have interest in developing the optimal load for it?
 

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This thread has digressed from the original question, but has, I think, become even more interesting and relevant to those of us shooting and reloading for the Langgewehr, K11 and K31.

I used the term "system" because the rifles in question must be evaluated in the context of the ammunition used.
GP11 was designed for the long rifle. It was used with the shorter K11 because it was the standard service round. Understandably, the K11 was expected to shoot the same ammunition used in the longer rifle and the higher MV achieved with the extra 7"-8" of barrel. Then came the K31, with a different chamber. As Meerkoos has documented, the K31 performed better with the GP11 ammunition designed for the Langgewehr and its longer barrel. Colonel Furrer managed to optimize performance of GP11 in a shorter barrel. Let us not overlook this bravura ballistic engineering!

So the question arises: can the 7.5x55 be tailored to optimize performance of the K11? "P" has already shown what can be down with tailored loads for the Langgewehr and K31. I don't think the K11 should be dismissed owing to its short barrel. Why bother with the K11? Well, this shooter's old eyes do better with the K11's rear sight located 4"/10 cm further away from the shooter's eye than the K31's.

So, does anyone else that enjoys shooting the K11 have interest in developing the optimal load for it?
If this helps in better understanding the Kar. 31 - GP 11 system, here is some data from the GP 11 TDP, dated Nov. 1945
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Distance-pressure curve of GP 11 in various barrel lengths.
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Time-pressure curve
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I am no expert in internal ballistics, but since the "end of powder combustion" is stated in both graphs, it is interesting to see that the Kar. 31's barrel length can be argued as being "more optimal" than the Ig. 11's, in the sense that there is no wastage of barrel length for marginal (even negative) performance gains!
 

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Good morning Leon and Meercoos. Thank you very much for the charts, and I do find it all extremely interesting and pertinent, and I am going to print all of them for ourselves. My son will find all; of this interesting, however all the charts in the world are not going to change 40 years of load data collecting and comparisons for me. Granted, none of my research was done with GP 11 projectiles and my findings with various projectile profiles and powders are not going to be a good comparative for what your charts and explanations show. My load data is enough for me to pit my G11's against my K31s all day long.

Leon, the only reason I did not include the K11 all those years ago is because my initial (and very few) comparisons that were not logged in simply showed the K11 to be not quite as accurate as either of the other two, however, I'm willing to take the time this summer to see what kind of load data I can find that lends itself to the K11 rifle. It's a good reason to get me out on the range and to the shoot shed, albeit with a walker and cane
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now. Using the Accurite Rest does not require me to physically hold rifle which I can no longer do anyway.

Now that we've discussed this, I'm actually looking forward to taking the K11's in the armory and run these tests. I will be using Swiss National Match boxer primed brass, so with the kind of case prep that we do, I should be able to get some rather accurate results as pertains to performance of each rifle. I will be sure to post results as I am able to get them. My son produces 4' x 8' sheets with multiple targets on them so I will be using at least one sheet for each rifle.

This is a shot of my son making a target change in the winter, and I'm certainly glad this is going to happen during the summer.
In order for us to continue gathering load data during the winter with snow on the ground, we had to resort to using what we call a "coffin" in order for the sensors to track the projectile without the intense reflection from the snow and sun. We have since begun using infrared sensors, and that solved the problem. The Shoot-Shed, (heated and lit) has two ports, the lower one for shooting prone and the upper one for using the Acurrite right shooting rest . Our maximum range is 500 yards.
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Quite honestly , most of the folks I know who actually care about accuracy in Swiss arms (i.e. other than shooting many 5 shot groups from the bench and selecting the best for retention) are shooting them in Swiss shooting societies.

When it matters then (shooting official events), You have a simple choice: GP11 or GP11. You can also shoot GP11 for score in Federal events. Anytime it matters, you shoot GP11. So the effort I have seen in setting up for accuracy is: The rifle is regulated for GP11, not the ammunition to the rifle. The same would be true if you plan to use the K11, it is legal to set it up for competition with a front and rear aperture (since 1973 in fact) , but I do not know anyone who has bothered.

If one was interested in seeing how well you could make a K11 shoot, the most likely place to focus on would be the front barrel bearing. Back when the M1903 Springfield was the US National match arm in the 1930s, they used to put in spring shims made from M1903 clips to maintain a uniform vibration pattern. So the brave soul who might want to tune the K11 might find a small amount of cork damping in the front barrel bearing, (in the top slot) might work wonders.

Now a properly regulated K31 with between 2000 and 6000 rounds down the tube will shoot something like a 98.6% on the A10 with 1970s though 1990s production. Not sure about the new stuff. Based on test targets, and according to Meerkoo's data, a properly regulated K31 in 1934~35 was capable of a 99.2% plus score on a A10 target. But in 1934 that would mean a new rifle, likely less than 1000 rounds down the tube. So the ammunition quality between 1934 and what is currently available on the US market (pre 1994) is not likely an issue.

The reality is the best 10 shot score I have seen from a sling firing K31 rifle shooter was a 97 on the A10 @ 300 M, his prior stage being a 91 so the Einselwettschiessen overall score was a 188. A 94% average, which is pretty good. The best 10 shot score on a scaled 100 yard A10 target was a 95, I have seen two shooters do that prone in 8 years. So for practical purposes it is not the ammunition that limits us in a shoot when firing on the A10, it is the fact that the A10 is a hard target to put 20 shots down the middle, on a range with no scope for mirage tuning, with a hasty sling and a 4 KG rifle which is not forgiving of hold errors.
 

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well I have to eat some crow, in deference to Leon and his handloading efforts.

Shooter I know who is very accurate conscious showed me some of his 3 shot groups, fired from a bench with a G96/11, with a Swiss products scope mount and an expensive Leopold scope. Nothing done to the rifle but careful cleaning of bore when he got it (chemical only).

Very small indeed, I think most folks would be pleased if they got that out of a "trued" Remington 700 with a 308 Bartline barrel. Lets just say the 112 year old 1909 year rifle with his handloads would give Federal 308 match out of a match tuned 700 a run for its money if the groups were as consistent as those G96/11 ones shown me. He said they were selected but the run of the mill ones were not that much larger. It has given me a lesson in what a bench rest shooter and handload specialist can do with a G11.

apparently the "bullet" to use is the 174 grain Berger match bullet, specifically this one:

Berger Bullets | 30 Caliber 175 Grain Long Range BT Target

I stand corrected relative to my comment above regarding match shooters.
 

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Fritz's posts above turned on another light on this discussion. We can talk about "instrumental accuracy" or results shooting carefully made ammunition in a rifle in a test fixture and "practical accuracy" with the same ammunition and the same rifle fired from the shoulder.

When I said I enjoy shooting my K11 more than a K31, that is the result of this differentiation. I don't shoot from a fixture, but I do shoot from a bench with a support. In that scenario the K31 is the tighter shooter. But if I shoot standing, that is where I find more satisfaction with my K11. Disclaimer: I am not a great shot; I am competent and can still shoot well enough to be "combat effective." "Combat effective" means putting bullets on a target where it hurts; groups are irrelevant when you only get, and need, one shot. Same applies to hunters.
So for my body build, shooting experience, and the whims of the range gods, the K11 just "fits" me better.
 

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well I have to eat some crow, in deference to Leon and his handloading efforts.

Shooter I know who is very accurate conscious showed me some of his 3 shot groups, fired from a bench with a G96/11, with a Swiss products scope mount and an expensive Leopold scope. Nothing done to the rifle but careful cleaning of bore when he got it (chemical only).

Very small indeed, I think most folks would be pleased if they got that out of a "trued" Remington 700 with a 308 Bartline barrel. Lets just say the 112 year old 1909 year rifle with his handloads would give Federal 308 match out of a match tuned 700 a run for its money if the groups were as consistent as those G96/11 ones shown me. He said they were selected but the run of the mill ones were not that much larger. It has given me a lesson in what a bench rest shooter and handload specialist can do with a G11.

apparently the "bullet" to use is the 174 grain Berger match bullet, specifically this one:

Berger Bullets | 30 Caliber 175 Grain Long Range BT Target

I stand corrected relative to my comment above regarding match shooters.
It could be interesting to see 10 or 20-round groups from that same rifle... 3-round groups sound too statistically insignificant to prove anything in terms of precision!
 

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Meerkoos,

From a mathematical point of view I agree completely. You cannot really make any kind of a definitive accuracy statement without a statistically significant sample size. Rifle competitor view sub 10 shot groups of little value, with a 17 to 22 shot group being much more meaningful in terms of what to expect in a competitive string, being it a 17 shot 900 M Palma string, 22 shot 600 Yard NRA string, or a 20 shot 300M Einselwettsciesssen.

However there is also another side: There is a long tradition of rifle shooters who tune their rifles and loads to get very small repeatable groups, typically based on 3 to 5 shot groups. This shooting method rose out of the extensive hunting culture that exists in the US. Bench rest shooting was an outgrowth. These shooters do a lot to minimize the variability of all aspects of cartridge, from truing primer pockets, weighting cases, annealing and checking bullet pull tension, special selection of primer lots, using a drop tune to get IMR grains to align vertically, etc. Their load quantities are measured in 20 to 40 round lots, not 1000 round lots as is typical of full bore competitors in the US.

Now some 25 to 35 years ago The NRA magazines did a comparison with a trued Remington 700 and Federal gold 308 match/handloads, firing something like 20, 5-shot groups. As they reduced all these variable's, the variation they saw in 5 shot groups diminished, to the point where they could predict with some reliability the size of said 5 shot groups. While each 5 shot group was statistically insignificant, the 20 5-shots groups fired and published were not. These "tuned" loads could be depended on to shoot a 0.xx MOA group consistently. That for me has always been the iron test of a shooter claiming "0.xx" group- 3 to 5 shot accuracy: Can he sit down and shoot such a group on demand, and if not, can he shoot 2 out of 3 groups that are below that size, with the one exceeding being close to the claim. Most fail, but not all, and the notable exception is folks who practice bench rest techniques.

So while it is true that the statistical veracity and repeatability of anything published on 3-shot groups is subject to selection of good groups and omission of bad, if you have an honest experimenter who has consistent results it is not something to be ignored. The chap who shared the results was one such person. I did not publish the size as, well frankly it was in the realm of what one would not believe. I would not have believed it but I saw the groups, I daresay the Swiss products prognostication that you can achieve high accuracy with a G11 rifles from the bench seem to be true. It is not chasing unicorn farts.

Also I should mention that the shooter had high praise for the Swiss products G11 scope mount. The mounting of the precision scope to match rifle is a subject of some care and concern to get good results and not to apply stress to either the rifle or scope tube. Apparently Swiss products approach really works.
 
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