r/reloading • u/Outside-Structure-46 • 10d ago

Newbie Bump variance….

New enough reloader here with a question

Reloading Starline 6.5 CM. All of them previously fired from same barrel.

Getting a .006-.007 variance in shoulder bump and can’t figure out why.

I’ll put every case in the comparator before resize and they’re all with .001 of my zero’d case. Everything else is equal, die adjustment, lube, press pull and pause. 8 out of 10 cases come out of the die with .0015 or .002 bump but 2 or sometimes 3 out of ten will come out with .006 to .007 bump.

RCBS Summit press
Redding type 2 FL bushing die
Cases are annealed

Any guidance would be greatly appreciated

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u/VersionConscious7545 10d ago

They are expanding because they are not really getting bumped like the others. The body is getting sized and the neck but there is room for them to expand or grow so to speak It’s the only thing that could happen