I had a similar issue with my 450-400 using 320gr WFN and 400gr LFN. The throat was a bit short for those bullets seated to the crimp groove, they had to be "breech seated" a bit. Got a 408 sizer from Buffalo and ran that up to the front band, sized the bands to 411. with the springback, the nose came back to about 4095, worked well. Been using wheel weights and water dropping them. Ran the 320's to 2050 with Blue lube to match the factory 400gr load. Haven't bothered to run the 400's up past 1880 yet. I like shooting the 320's better, easier on the constitution with a #1. I definitely like both of those boolits though.
