I just got a new lyman mold .457 diam. 475 gr. gas check. My problem is the gas checks are loose and fall off even after installing them with a sizer. I am using hornady crimp ons. I miked the base of the bullet and the inside of the gas check and there is a 5 thou. differance between the two. the bullet is the smaller. Do I have a problem, can I use them and if so how do you keep it on? the gas checks are a good fit with the other 457/ 458 bullets that I load.
Thanks in advance, Stubert