I just traded for a 10" 357 mag. Contender barrel and bought a Lee 358-180-rfn group buy mold from a couple of members here. Was doing some measuring and it looks like this barrel has little or no throat (one of the earlier barrels from what I gather). Looks like I will only be able the seat the bullet to a COL of about 1.560", so I will not be able to crimp in the crimp groove. I also measured it with RCBS 35-180-Sil & 35-200-FN boolits. I will not be able to seat any of these out enough to crimp in the groove. Since this is a single shot, not being able to crimp in the groove is not a big deal, but I would also like to be able to shoot the same ammo. in my GP-100 crimped in the groove.
So my question is, can I just run a 357 throat reamer in by hand until a bullet seated in the crimp groove will chamber?
I am also planning to get a 14" 357 mag. Contender barrel (maybe & NEF, too) to rechamber to 357 max. I have seen a post hear about someone using a .381 chucking reamer by hand to extend a 357 mag. chamber to a max. chamber in a NEF. I would assume you could do the same in a Contender. Could you then use the same 357 throat reamer to do the throat for the max?