So I go out to the range to fire some Federal and Remington Factory Loaded cartridges today, comparing them to some handloads (using Fed brass) that have been fired only twice so far and FL sized.
they are all "measured out" prefiring, hoping to find my headspace numbers and trying to "understand the instructions" on my RCBS Precision Mic - for .270WSM
Can you guys check this out and tell me if this looks right?
Factory Remington 130gr Core-lokt FSP (average thru 5 rounds)
Prefired -.003 Post Fired -.001, then Resized -.004
Factory Federal 130gr Power shok SP
Prefired -.0035 Post Fired -.0005, then Resized -.003
Handloads after one time FL sizing and Firing then FL sized a second time
Prefired -.0035 Post Fired -.002, then Resized -.004
The FL Sizing die was not changed or adjusted thru all these sizings.
My main question, before I continue to FL size these on this Die Adjustment, is it ok for these to be all in the (-) as in all below the ANSI minimum? Does this make sense or do you guys see something wrong in what I am doing? Or in the headspace dimensions of this rifle, a Sako 85. New with less than 500 rounds thru the barrel. Also why is there any variation in the Headspace of a fired round? Different brass, or what?
Thanks for the advice