Undersized brass, large chamber & light loads will have primers backed out, some Rem Whelen brass was small as I recall.
Fire Form your brass and work up to mid pressure loads and you should be fine, brass could be hotter than normal with light loads
if brass was undersize, any soot on shoulder of fired brass?
Not much of a shoulder on the Whelen easy to create brass headspace issue by oversizing brass.
Best load in my Rem 7600 35 Whelen, RP Whelen brass, CCI 200, 56 GR of IMR 4320, Speer 250 gr.
Last edited by kk alaska; 06/10/18.
