That's pretty good CW.
I use a Lyman 45 to seat checks but never force them. First I snap the check on the base and then seat/crimp in the 45 before moving over to the press for final sizing in a Lee-type die.
If your checks have to be forced on they will plow up a ring of lead and be eccentric to the bullet body, guaranteed.
If the check is too tight to fit the shank either expand it, custom make your own checks, or get a properly made bullet mould. The only reason I "seat" gas checks is to crimp them on the shank under pressure using the tapered entrance of an H die.