I'm shooting a factory barreled Remington LTR in .308.
I'm loading 168gr SMK with Lapua brass, CCI BR primers, 43.8 of Varget.
Trimmed to length, primer pockets reamed, neck chamfered and deburred.
Primed with RCBS hand priming tool.
Lee collet die neck sized.
Although, these loads had the shoulder bumped back prior to this loading with a Redding body die. I did not chrono them prior to shoulder bump so no data to compare to there but the groups seem to be about the same.
Powder dropped with Chargemaster 1500.
Bullet seated with RCBS Competition seater die.
I'm getting a Standard deviation of 22 FPS with Extreme Spread of it the 30-34fps range. I'm using a Pact Mark IV chrono with standard sky screens. It seems there are only a few rounds that have a significant variance to make the ES and SD significant. I chrono'd some pistol loads and my SD was in the 8fps range with ES around 12fps or so.
Any input as to why this could be and what to do to tighten things up? And yes, it seems to effect my groups as the more consistent the velocities the tighter the groups. I was shooting at 200 yds.
Thanks for helping me out.
21Bravo
aka Craig P. in MO
I'm loading 168gr SMK with Lapua brass, CCI BR primers, 43.8 of Varget.
Trimmed to length, primer pockets reamed, neck chamfered and deburred.
Primed with RCBS hand priming tool.
Lee collet die neck sized.
Although, these loads had the shoulder bumped back prior to this loading with a Redding body die. I did not chrono them prior to shoulder bump so no data to compare to there but the groups seem to be about the same.
Powder dropped with Chargemaster 1500.
Bullet seated with RCBS Competition seater die.
I'm getting a Standard deviation of 22 FPS with Extreme Spread of it the 30-34fps range. I'm using a Pact Mark IV chrono with standard sky screens. It seems there are only a few rounds that have a significant variance to make the ES and SD significant. I chrono'd some pistol loads and my SD was in the 8fps range with ES around 12fps or so.
Any input as to why this could be and what to do to tighten things up? And yes, it seems to effect my groups as the more consistent the velocities the tighter the groups. I was shooting at 200 yds.
Thanks for helping me out.
21Bravo
aka Craig P. in MO