I have some 32-20 bullets that will not chamber in my Marlin when seated to the crimping groove. They will feed through the action fine but the throat is too short.

I’m thinking about trimming some cases .085 shorter and see how that works. My main problem, I think, is going to be that neither my bullet seating die nor my Lee FC die is going to be able to crimp a case that short. I don’t think Lee will charge much to modify one or the other.

This would leave me with a case neck approximately .260 long.

Comments???

That seems a reasonable approach. You might be surprised to learn that either or both of your dies may still work fine (after proper adjustment). If not, any machinist whatsoever can turn 0.1" off the bottom of either die and add a slight chamfer to the inner edge.

I had to do that when I worked on the superb little .41 Special - the .41 Magnum die wouldn't crimp the shorter cases. Ten minutes at the lathe and no problem no mo'.

Re the shorter neck, just be sure your bullets don't project down below the bottom of the neck. Cast bullets are ruined by powder gases if any portion of the bullet shank (side) is exposed below the neck. Just hold a bullet up next to the neck with the bullet base at the shoulder junction and mark where the crimp groove meets the neck. That's as short as you can go.

The location of the bullet's base is going to be controlled by the throat, no matter if I trim them back or not. The base lands somewhere along the (practically nonexistant) shoulder of the case.

Ken,
I use BTB cast bullets in all of my Marlins (.32-20, .30-30, .35Rem, 444 and 45-70) and don't seat any of them crimped in the crimp groove. I set my OAL so that the bullet just touches the lands and use the Lee FCD and crimp. In my .32-20, I use the BTB 115g FNPB and the crimp groove ends up slightly inside the neck. My cases are Starline and are at 2.85" length.

Dan

The location of the bullet's base is going to be controlled by the throat, no matter if I trim them back or not. The base lands somewhere along the (practically nonexistant) shoulder of the case.

That's true...trtimmed or not, when seatged to the same OAL will have the same internal volume.

Sometimes you just have to to get a round that is both crimped and inside you outer OAL limit. Be nicer if you didn't have to trim the cases, but if you are dead-set on using that bullet, have few choices. Might load a couple with no crimp (if the bullet/case fit is tight enough), carefully measure their OAL and write it down,load them FIRST, shoot a magazine stoppping before the test rounds, and then measure them for any change in OAL.

After pondering this for several days. I'm now considering opening the throat of my rifle up. In this case I should say "put a throat in" cause it don't have one at all now.

Sounds like a good solution. A gunsmith shouldn't have much trouble opening up a bit of throat for you.