So another thread got me interested in this topic recently and I had the opportunity to collect some data today.
I needed to fire form 50 cases for my new APR
6.5 Creedmoor
20" barrel
Barrel was brand new.
Unfired Peterson brass full length sized, trimmed, neck turned, reamed, faced, chamfered, and deburred. The necks all seemed to have adequate tension-- I did not size them, which may add some scatter to the data. the SD is pretty high for both sets, but it also took a few rounds for the barrel to settle in, which added to the SD.
129 gr. SST
42 gr. of RL-17
I didn't Q/C the charge weights like I normally do since I was just fire forming, but I dialed the first one and all were thrown with a Redding BR-30, which is very consistent normally.
I shot groups of 5, starting unsuppressed, then adding the can, then back, through 50 rounds. Chrono'ed with a Magnetospeed. The first round with the can didn't read properly because I had too much gap. Round 40 failed to feed because I accidentally pulled a 7mm button through it after the neck got dinged and didn't resize the neck far enough down to feed.
One small set of data and I didn't know what to expect, except that some folks on here said the can would add velocity. I grouped "shot pairs" even though they weren't shot that way because it seemed to present the comparison in the best way. Scatter plots didn't really say much.
I needed to fire form 50 cases for my new APR
6.5 Creedmoor
20" barrel
Barrel was brand new.
Unfired Peterson brass full length sized, trimmed, neck turned, reamed, faced, chamfered, and deburred. The necks all seemed to have adequate tension-- I did not size them, which may add some scatter to the data. the SD is pretty high for both sets, but it also took a few rounds for the barrel to settle in, which added to the SD.
129 gr. SST
42 gr. of RL-17
I didn't Q/C the charge weights like I normally do since I was just fire forming, but I dialed the first one and all were thrown with a Redding BR-30, which is very consistent normally.
I shot groups of 5, starting unsuppressed, then adding the can, then back, through 50 rounds. Chrono'ed with a Magnetospeed. The first round with the can didn't read properly because I had too much gap. Round 40 failed to feed because I accidentally pulled a 7mm button through it after the neck got dinged and didn't resize the neck far enough down to feed.
One small set of data and I didn't know what to expect, except that some folks on here said the can would add velocity. I grouped "shot pairs" even though they weren't shot that way because it seemed to present the comparison in the best way. Scatter plots didn't really say much.
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