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Wyoredman · January 28, 2013, 10:48 AM

I attribute the large ES and SD to having used mixed headstamp brass. When loading to near full case capacity, the powder in some of the smaller volume cases compresses more. This is just my theory, anyway.

I have some G.F.L. headstamps that were almost 100% full while the LC and PMC still had some room left in the neck with 26.5 gr of varget. This is what I attributed the velocity spread to, but I didn't keep track of brass durring shooting for velocity over the chrony.

EDIT:
BTW - if I disreguard the top two velocities (both 3300) and the lowest two velocities (both <3200) the Average for the remaining 16 measurements is still 3252 and the SD drops to 19.5 with an ES of 68fps. Alot better but still not below 10 SD.

January 28, 2013, 10:48 AM	#25
Wyoredman Senior Member Join Date: September 6, 2011 Location: Wyoming Posts: 1,352	I attribute the large ES and SD to having used mixed headstamp brass. When loading to near full case capacity, the powder in some of the smaller volume cases compresses more. This is just my theory, anyway. I have some G.F.L. headstamps that were almost 100% full while the LC and PMC still had some room left in the neck with 26.5 gr of varget. This is what I attributed the velocity spread to, but I didn't keep track of brass durring shooting for velocity over the chrony. EDIT: BTW - if I disreguard the top two velocities (both 3300) and the lowest two velocities (both <3200) the Average for the remaining 16 measurements is still 3252 and the SD drops to 19.5 with an ES of 68fps. Alot better but still not below 10 SD. __________________ Go Pokes! Go Rams! Last edited by Wyoredman; January 28, 2013 at 12:48 PM.