09-02-2023, 08:56 AM
Those measurements look normal, although on the generous side. My expansion from sized to bullet release is 0.008. Yours is .013".
SAAMI Grendel chamber neck spec is listed as .300 so yours is on the limit, but acceptable. My spent cases are .2940 so that is from a tighter chamber (Lilja).
Could it be lube? Are you lubing the necks?
Your resized brass is a result of the expander ball widening it back out again to OD 0.287", as it gets dragged out. If you take out the sizer stem/expander ball what does the neck get squeezed down to? I have removed the expander ball in the Forster and the sized OD is 2.860". Have lost count of the number of reloads but maybe 10+ (Lapua cases).
SAAMI Grendel chamber neck spec is listed as .300 so yours is on the limit, but acceptable. My spent cases are .2940 so that is from a tighter chamber (Lilja).
Could it be lube? Are you lubing the necks?
Your resized brass is a result of the expander ball widening it back out again to OD 0.287", as it gets dragged out. If you take out the sizer stem/expander ball what does the neck get squeezed down to? I have removed the expander ball in the Forster and the sized OD is 2.860". Have lost count of the number of reloads but maybe 10+ (Lapua cases).