I've noticed that a few months ago, I was able to pull off some awesome groups with my 125gr Speer load. Since that time, I don't think I've been able to get the groups back to where they were. I decided to try an experiment. I got a batch of 50 cases that were matched by weight and all Winchester brass from roughly the same time period. When I sorted them over a year ago, they were all within 1 grain of each other. This batch has been fired 4 times.
The rifle is an LRB M14SA with a 22" medium weight Criterion barrel, 1:12" twist. I bedded the action myself into a carbon graphite kevlar stock. 2500 rounds through the barrel at the start of the day. The barrel hadn't been cleaned in about 80 rounds and I shot 10 today to warm up the rifle. So at the end of the day, it's been about 140 rounds since the barrel was cleaned.
I randomly picked 25 cases and I annealed them with a Bernz-O-Matic. I did some research during the process...
http://forum.accurateshooter.com/index.php?topic=3848611.0
I loaded up the whole batch of 50 cases with 45 grains of IMR-4895 and Speer 125's. I shot ten 5-shot groups, alternating shooting groups between annealed and non-annealed so as to see if fouling and barrel heat would affect the groups identically or not. It took about an hour and a half to shoot all 50 cases.
All groups were shot off the bench at 100 yards, sand bagged and scoped.
I had one flyer that I called on the third group of the annealed batch. For consistency sake, I'll omit the flyer. I knew I pulled it to the right when the shot broke, confirmed with my spotting scope.
I also made scope adjustments after the first and third group of the annealed sets, so that explains the POI shift.
Group sizes are as follows for annealed set:
Group 1: 1.158"
Group 2: 1.406"
Group 3: 1.047" (flyer omitted). With the flyer, the group was 2.110"
Group 4: 1.297"
Group 5: 1.383"
Average group size:1.2582"
Max/Min Spread: 0.359"
Group sizes are as follows for un-annealed set:
Group 1: 1.489"
Group 2: 1.864"
Group 3: 0.935"
Group 4: 1.039"
Group 5: 1.614"
Average group size: 1.3882"
Max/Min Spread: 0.929"
Total 10-group average: 1.3232"
My annealed groups seem to be more consistent than the un-annealed groups and I like the max/min spread difference. I think I'm going to try annealing my brass between reloadings for a while to see what happens. After today's trip, the cases have been fired 5 times but maybe only half that with the gas on. I'm going to run these a few more times with the gas off and see what happens.
I also think my bedding might be wearing out. It's been 19 months since I bedded it and maybe 1000 rounds since then. It may be time for a skim-bed.
Just thought I'd share in hopes that some might find this interesting. Thanks to all those who gave me advice on the other thread.
Tony.
The rifle is an LRB M14SA with a 22" medium weight Criterion barrel, 1:12" twist. I bedded the action myself into a carbon graphite kevlar stock. 2500 rounds through the barrel at the start of the day. The barrel hadn't been cleaned in about 80 rounds and I shot 10 today to warm up the rifle. So at the end of the day, it's been about 140 rounds since the barrel was cleaned.
I randomly picked 25 cases and I annealed them with a Bernz-O-Matic. I did some research during the process...
http://forum.accurateshooter.com/index.php?topic=3848611.0
I loaded up the whole batch of 50 cases with 45 grains of IMR-4895 and Speer 125's. I shot ten 5-shot groups, alternating shooting groups between annealed and non-annealed so as to see if fouling and barrel heat would affect the groups identically or not. It took about an hour and a half to shoot all 50 cases.
All groups were shot off the bench at 100 yards, sand bagged and scoped.
I had one flyer that I called on the third group of the annealed batch. For consistency sake, I'll omit the flyer. I knew I pulled it to the right when the shot broke, confirmed with my spotting scope.
I also made scope adjustments after the first and third group of the annealed sets, so that explains the POI shift.
Group sizes are as follows for annealed set:
Group 1: 1.158"
Group 2: 1.406"
Group 3: 1.047" (flyer omitted). With the flyer, the group was 2.110"
Group 4: 1.297"
Group 5: 1.383"
Average group size:1.2582"
Max/Min Spread: 0.359"
Group sizes are as follows for un-annealed set:
Group 1: 1.489"
Group 2: 1.864"
Group 3: 0.935"
Group 4: 1.039"
Group 5: 1.614"
Average group size: 1.3882"
Max/Min Spread: 0.929"
Total 10-group average: 1.3232"
My annealed groups seem to be more consistent than the un-annealed groups and I like the max/min spread difference. I think I'm going to try annealing my brass between reloadings for a while to see what happens. After today's trip, the cases have been fired 5 times but maybe only half that with the gas on. I'm going to run these a few more times with the gas off and see what happens.
I also think my bedding might be wearing out. It's been 19 months since I bedded it and maybe 1000 rounds since then. It may be time for a skim-bed.
Just thought I'd share in hopes that some might find this interesting. Thanks to all those who gave me advice on the other thread.
Tony.
