I had quite a few misfires with handloads put up in new Winchester brass in my Ruger 77 in .358 Win. The shoulder configuration is about the same as the Whelen.
The headspace of the rifle is proper, primers were properly seated and firing pin protrusion was in spec . I can only opine that the virgin brass was a bit short in the head to shoulder measurement. It could make a guy wonder if the cartridge design is flawed.
I put a heavier striker spring in the bolt but still had a few (but less than before) misfires. I haven't had any problem with reloads using previously fired brass, so the misfires had to be caused by a problem with the dimensions of the virgin brass.
Last edited by wildhobbybobby; 09/15/10.
