Ransom rest results- help with magazines

I had the opportunity to test some ammo in my  208 in a Ransom Rest today. While the groups are nicely sized, there are two distinct groups for each magazine. I have one Hammerli magazine and one modified M41 magazine. Loading and cycling has been 100%, but the groups are distinct, with different impact areas. How would I tune the magazine, so that the groups overlap? I’m not sure that this will make much difference at 25 yards, but the difference was severe for 50 yards. I had heard that magazines could make a difference, but I thought that once a round was in the chamber, the impact point would be similar.

Thanks for any insight

Joe 

Multiple tests are required to establish if it’s statistically significant. “Random Rest” techniques are also important. You can’t rely on just a couple datapoints. With a 22, l never noticed any magazine effects myself but I was only a Master….

When I test an autoloader in a Ransom rest, I replace the magazine before the last round in the previous magazine is fired.   This prevents the gun from locking back after the final round.   I find the lock back can affect the way the gun is held in the grip inserts.

Now frankly, I wouldn't expect the lock back to have much affect on a 22, but I find it does with a 45.

I will try that. I did find the first round out of the second magazine in the .45 I also tested today, to be a “flier” not bad, but out of group by at least an inch

Do you get the same results off sandbags?

rbwillnj wrote:When I test an autoloader in a Ransom rest, I replace the magazine before the last round in the previous magazine is fired.   This prevents the gun from locking back after the final round.   I find the lock back can affect the way the gun is held in the grip inserts.

Now frankly, I wouldn't expect the lock back to have much affect on a 22, but I find it does with a 45.

I neglected to mention that when you do the above you need to be VERY careful.   Firstly because you have a cocked firearm with a round in the chamber and secondly because you want to be careful not to disturb the gun in the grip inserts as you insert the new magazine.

I will sandbag the gun with the same two magazines as soon as I can get back to the range. I will post results

rbwwillnj- thank you, will do. I will do my best not to disturb the gun- safely

Just wanted to circle back. I sandbagged the gun over the weekend. I took the factory Hammerli magazine, shot 2 magazines (10 shots) went down range, and circled the grouping. I then did 2 magazines of the modified M41 magazine- went down range, and all the shots were still within the circle. So both magazines are shooting the same! Really strange that the magazines on the ransom rest showed two different groupings

Just saw a youtube where a gunsmith was talking about putting in a disconnector slot and how it also helped lessen your first round change of impact. Any truth to this?

joeangi wrote:Just wanted to circle back. I sandbagged the gun over the weekend. I took the factory Hammerli magazine, shot 2 magazines (10 shots) went down range, and circled the grouping. I then did 2 magazines of the modified M41 magazine- went down range, and all the shots were still within the circle. So both magazines are shooting the same! Really strange that the magazines on the ransom rest showed two different groupings

You likely bumped the gun when you changed mags in the ransom rest. A ransom rest is a good tool, but it is kinda like a milling machine or a lathe, some what simple to operate but a bit of an art to get absolute perfect results.