Are you sure those are gas check bullets ?These 45-70 were cast a year ago. I'd ordered some gas checks from Sage Outdoors so tried to put them on with my Lyman 450 today. The 2 standing up, take a look at pic. I'm using a .458 sizer. Didn't have the right top punch, that's not issue. Problem is the force to start it into the die almost takes the 450 to breaking point. Without the gas check it's easy into the die. Just the 500 gr made for checks, not trying to do non gas check 350s.View attachment 3084374