Leading issue in throat

[jonk]

Swiss 1889. 11 gr red dot. Lee 200 gr .309 bullet. Hornady gas check. Bore measures .3075X.298. ACWW.

It's leading a little in the throat but not in the bore beyond. 50/50 lube.

I'm thinking that the 1889 probably has a more generous throat than the K-31 though it LOOKS rather abrupt, I've never made a chamber cast. Nor do I have to seat bullets very deep in the case to get them to chamber.

Still, my initial guess would be a throat that's oversized compared to the bore. While I'm currently sizing at .309, I might bump that up to .311 and see how they chamber and shoot.

Reasonable analysis? Or other suggestions?

[MtGun44]

Probably burned rough and large - this is pretty much guarenteed to happen in any
rifle throat. Typically best results are to fit the boolit to the throat rather than to the
bore. You may find that a fatter boolit fixes this issue and shoots well. Cast or slug
up a throat slug to see what you really have.

[runfiverun]

could try the water drop also, you might be skidding.