Originally posted this in SnipersHide, but thought you guys may have some valuable insight/feedback. Thanks!
Let me preface this topic: I've read numerous posts, watched countless videos and many days tinkering with loads by charge and COAL. However, with regard to annealing, I've not yet encountered anything on the web that provides quantitative analysis of before and after results annealing with respect to accuracy and precision of groups. I'm sure it's available SOMEWHERE but haven't stumbled across yet... <br />
<br />
I inadvertently created the opportunity to test the consistency and accuracy of annealed brass vs. non-annealed and effects COAL (Cartridge OverAll Length, for those that aren't familiar), simultaneously under "ideal" conditions. I decided to begin annealing brass for first time as I recently purchased several hundred Lapua cases but they were on there 5th fire for the season and began to see groups open up without explanation. After annealing nearly 400 cases, I realized that I had 20 NON-annealed 5th fire cartridges remaining from the last batch. Perfect opportunity to test both variables (COAL and Annealed once fired brass) against a control group of at handloads from the prior batch. <br />
<br />
Below follows my procedure:<br />
- CONTROL GROUP: (10) rounds Sierra 2156c Palma 155gr with 45.2gr IMR4064 seated .020 from lands. This is the result of many rounds of testing various lengths and charges; it normally produces .6 to 1.2 MOA groups under good conditions (avg about .8 MOA over last 150 rounds). Brass was on 5th fire and was trimmed to 2.005" on 4th fire. Ammo had been loaded for approximately 3 weeks before today's test. The last rounds fired at 100yds averaged .75" only two weeks prior. This brass has only been neck sized on Lee Classic Single Stage since new. FWIW, I've NEVER fired consistent sub-half MOA groups with this load or rifle under any conditions; certainly close and had a few 1/2 minute groups on several occasions but average over life of rifle has been .85" with this load. <br />
<br />
- VARIABLE #1 - COAL REDUCED TO MAG LENGTH 2.815" (10) rounds of above (5th fire Lapua, 2156c, 45.2gr IMR 4064) but with bullets reseated to new COAL. <br />
- VARIABLE #2 - ANNEALED CASES - all ammo loaded to same spec with same process as CONTROL group but with only variable being newly annealed cases. These cases would now be smelled for first time since purchase and losing them 5 times.<br />
-VARIABLE #3 - BULLET to CASE "WELDING" - The exact term for this phenomena is escaping me, but I've read on a few occasions that reloading bullets and letting them sit is a bad practice as the copper jacket and case mouth can essentially bond more tightly over time, increasing variations in velocity due to inconsistent neck tension. This test does not truly have a control group as I didn't have newly seated, non-annealed CONTROL cases available. So the benchmark for this test is simply prior data over the last 150 rounds (spread over past 2-3 reload cycles and accumulated data from 600+ rounds with this load). Basically, I'm using the CONTROL Group as a test variable by comparing it to prior known data averages across the life of the rifle with this specific load which developed and shot over 600 rounds with this load since rifle was new. <br />
<br />
So here are the results of the test. First picture is of the test target:
<br />
<br />
This is picture of a final group shot after 15-20min cool down for vertical tracking test; 3-shot group. <br />
<br />
<br />
<br />
SUMMARY of Test:<br />
<br />
-VARIABLE #1 - COAL REDUCED TO MAG LENGTH 2.815" No surprises here... Just confirmation that the COAL (specifically bullet jump) affects accuracy by a considerable margin. I can post prior data groups for comparison if Anyone is interested but frankly, I think most hand loaders find out quickly that most barrels shoot well loaded closer to the lands. <br />
CONCLUSION: To use your magazine length ammo and shoot accurately, either find a bullet with long bearing surface (I've used 155 Scenars with great success) and short tip OR make sure your next barrel will be reamed to allow mag length bullets to seat closer to lands. <br />
<br />
-VARIABLE #2 - ANNEALED CASES. This is the real shocker and frankly I had to keep shooting groups to confirm what I was seeing. I hypothesized that annealing would simply allow easier sizing and prolong case life. I did not expect any differences in accuracy as the idea of uniform neck tension seems easy to accomplish with neck sizing operations. The actual accuracy/precision improvements are (in my case) MASSIVE: over 60% improvement over my long established average of .8" with this rifle and load (groups .179", .344, .383", and .494" with avg .350" vs .8" for prior data). <br />
CONCLUSION: Anneal more often and if you don't, you may consider running test this with your 3rd,4th or 5th cycle brass to see if it restores or even added any accuracy to your load. Took a bit of time to anneal (maybe 2hours for nearly 400 cases including all extra setup and cooling etc.) perhaps the single biggest improvement in my groups other than developing the load in the first place. <br />
<br />
-VARIABLE #3 - BULLET to CASE "WELDING" - this concept didn't seem to ring with me however, having the group sizes from the first two days after pressing bullets (.6-.85") vs the groups above (1"-1.5") there certainly seems to be some truth to this phenomenon. This may be in part due to the increasing hardness of the neck but I can't truly draw direct conclusion without a better control group to compare (I.e. Newly loaded 5th fire non-annealed brass with same charge and COAL).<br />
<br />
Here a few pictures the original control batch from two weeks prior; 100 rounds were loaded, with 50 at the 45.2 charge and and I believe I pushed around (9) 5-shot groups of different weights through the bore. I was re-testing various weight charges under the 2156c and simply confirm for fit for rifle: <br />
<br />
<br />
<br />
<br />
<br />
CONCLUSION: Load and shoot your rounds as close together as possible. If not possible, perhaps seat bullets slightly long and reseat to final depth with a day or two prior to firing. <br />
<br />
If you can see anything that I missed or draw different conclusions than I did, please reply. I am curious if anyone else has had similar experience before/after annealing multiple-fire cycles. <br />
<br />
Thanks and looking forward to your comments/replies!<br />
<br />
Edited: Thanks to SWThomas for feedback; changed wording for clarity and added some prior data and photos.<br/>
Let me preface this topic: I've read numerous posts, watched countless videos and many days tinkering with loads by charge and COAL. However, with regard to annealing, I've not yet encountered anything on the web that provides quantitative analysis of before and after results annealing with respect to accuracy and precision of groups. I'm sure it's available SOMEWHERE but haven't stumbled across yet... <br />
<br />
I inadvertently created the opportunity to test the consistency and accuracy of annealed brass vs. non-annealed and effects COAL (Cartridge OverAll Length, for those that aren't familiar), simultaneously under "ideal" conditions. I decided to begin annealing brass for first time as I recently purchased several hundred Lapua cases but they were on there 5th fire for the season and began to see groups open up without explanation. After annealing nearly 400 cases, I realized that I had 20 NON-annealed 5th fire cartridges remaining from the last batch. Perfect opportunity to test both variables (COAL and Annealed once fired brass) against a control group of at handloads from the prior batch. <br />
<br />
Below follows my procedure:<br />
- CONTROL GROUP: (10) rounds Sierra 2156c Palma 155gr with 45.2gr IMR4064 seated .020 from lands. This is the result of many rounds of testing various lengths and charges; it normally produces .6 to 1.2 MOA groups under good conditions (avg about .8 MOA over last 150 rounds). Brass was on 5th fire and was trimmed to 2.005" on 4th fire. Ammo had been loaded for approximately 3 weeks before today's test. The last rounds fired at 100yds averaged .75" only two weeks prior. This brass has only been neck sized on Lee Classic Single Stage since new. FWIW, I've NEVER fired consistent sub-half MOA groups with this load or rifle under any conditions; certainly close and had a few 1/2 minute groups on several occasions but average over life of rifle has been .85" with this load. <br />
<br />
- VARIABLE #1 - COAL REDUCED TO MAG LENGTH 2.815" (10) rounds of above (5th fire Lapua, 2156c, 45.2gr IMR 4064) but with bullets reseated to new COAL. <br />
- VARIABLE #2 - ANNEALED CASES - all ammo loaded to same spec with same process as CONTROL group but with only variable being newly annealed cases. These cases would now be smelled for first time since purchase and losing them 5 times.<br />
-VARIABLE #3 - BULLET to CASE "WELDING" - The exact term for this phenomena is escaping me, but I've read on a few occasions that reloading bullets and letting them sit is a bad practice as the copper jacket and case mouth can essentially bond more tightly over time, increasing variations in velocity due to inconsistent neck tension. This test does not truly have a control group as I didn't have newly seated, non-annealed CONTROL cases available. So the benchmark for this test is simply prior data over the last 150 rounds (spread over past 2-3 reload cycles and accumulated data from 600+ rounds with this load). Basically, I'm using the CONTROL Group as a test variable by comparing it to prior known data averages across the life of the rifle with this specific load which developed and shot over 600 rounds with this load since rifle was new. <br />
<br />
So here are the results of the test. First picture is of the test target:
<br /><br />
This is picture of a final group shot after 15-20min cool down for vertical tracking test; 3-shot group. <br />
<br /><br />
<br />
SUMMARY of Test:<br />
<br />
-VARIABLE #1 - COAL REDUCED TO MAG LENGTH 2.815" No surprises here... Just confirmation that the COAL (specifically bullet jump) affects accuracy by a considerable margin. I can post prior data groups for comparison if Anyone is interested but frankly, I think most hand loaders find out quickly that most barrels shoot well loaded closer to the lands. <br />
CONCLUSION: To use your magazine length ammo and shoot accurately, either find a bullet with long bearing surface (I've used 155 Scenars with great success) and short tip OR make sure your next barrel will be reamed to allow mag length bullets to seat closer to lands. <br />
<br />
-VARIABLE #2 - ANNEALED CASES. This is the real shocker and frankly I had to keep shooting groups to confirm what I was seeing. I hypothesized that annealing would simply allow easier sizing and prolong case life. I did not expect any differences in accuracy as the idea of uniform neck tension seems easy to accomplish with neck sizing operations. The actual accuracy/precision improvements are (in my case) MASSIVE: over 60% improvement over my long established average of .8" with this rifle and load (groups .179", .344, .383", and .494" with avg .350" vs .8" for prior data). <br />
CONCLUSION: Anneal more often and if you don't, you may consider running test this with your 3rd,4th or 5th cycle brass to see if it restores or even added any accuracy to your load. Took a bit of time to anneal (maybe 2hours for nearly 400 cases including all extra setup and cooling etc.) perhaps the single biggest improvement in my groups other than developing the load in the first place. <br />
<br />
-VARIABLE #3 - BULLET to CASE "WELDING" - this concept didn't seem to ring with me however, having the group sizes from the first two days after pressing bullets (.6-.85") vs the groups above (1"-1.5") there certainly seems to be some truth to this phenomenon. This may be in part due to the increasing hardness of the neck but I can't truly draw direct conclusion without a better control group to compare (I.e. Newly loaded 5th fire non-annealed brass with same charge and COAL).<br />
<br />
Here a few pictures the original control batch from two weeks prior; 100 rounds were loaded, with 50 at the 45.2 charge and and I believe I pushed around (9) 5-shot groups of different weights through the bore. I was re-testing various weight charges under the 2156c and simply confirm for fit for rifle: <br />
<br />
<br />
<br />
<br /><br />
CONCLUSION: Load and shoot your rounds as close together as possible. If not possible, perhaps seat bullets slightly long and reseat to final depth with a day or two prior to firing. <br />
<br />
If you can see anything that I missed or draw different conclusions than I did, please reply. I am curious if anyone else has had similar experience before/after annealing multiple-fire cycles. <br />
<br />
Thanks and looking forward to your comments/replies!<br />
<br />
Edited: Thanks to SWThomas for feedback; changed wording for clarity and added some prior data and photos.<br/>
