Need an assist with reloading. Kind of feel like a dummy as I have been reloading for a long time, but this one has me pulling my hair out.
I finished my .280ai build this week and bedded it yesterday. I am wanting to work up a load for this rifle for the upcoming bear season, which begins in eight days.
I have once-fired factory casings I shot just to get on paper and do a scope tracking test... and to have cases that fit my chamber.
I FL sized the brass using RCBS full length dies and achieved my .002" shoulder bump. I removed the expander ball from the RCBS die. I then went to neck size the cases using my Lee Collet die with mandrel. Necks sized okay, but here is the weird part: My .002 " shoulder bump grows to .005" shoulder bump just from collet/mandrel sizing! I am not bumping the neck with the Lee die. It is a .280 Rem Collet, which Lee says works fine for the ai. As with all Lee collet dies, they are machined to accomodate the ai version of the parent cartridge. So, since my headspace/shoulder bump had grown by .003", I again sized the cases in the RCBS die to get my desired .002" shoulder bump. No problem... but then the necks are WAYYY too tight after re-sizing in the RCBS die. So, when I re-do the Lee neck sizer I again gain .003" more in headspace.
Am I missing something? Has anybody experienced this?
Thanks.
I finished my .280ai build this week and bedded it yesterday. I am wanting to work up a load for this rifle for the upcoming bear season, which begins in eight days.
I have once-fired factory casings I shot just to get on paper and do a scope tracking test... and to have cases that fit my chamber.
I FL sized the brass using RCBS full length dies and achieved my .002" shoulder bump. I removed the expander ball from the RCBS die. I then went to neck size the cases using my Lee Collet die with mandrel. Necks sized okay, but here is the weird part: My .002 " shoulder bump grows to .005" shoulder bump just from collet/mandrel sizing! I am not bumping the neck with the Lee die. It is a .280 Rem Collet, which Lee says works fine for the ai. As with all Lee collet dies, they are machined to accomodate the ai version of the parent cartridge. So, since my headspace/shoulder bump had grown by .003", I again sized the cases in the RCBS die to get my desired .002" shoulder bump. No problem... but then the necks are WAYYY too tight after re-sizing in the RCBS die. So, when I re-do the Lee neck sizer I again gain .003" more in headspace.
Am I missing something? Has anybody experienced this?
Thanks.
