[garrisonjoe]

I've used a SuperSizer 777 successfully for that. Adjust to minimum amount of resizing you need to take care of the problem. If you are leary, size down some primer-only hulls, wearing your eyes and ears protection, as a test. Just don't put your head directly above the SuperSizer.

When doing this in a 12 gauge, there is at least 0.20" of plastic (or paper) hull base between the sizing force and the primer. And, you are squeezing sideways, not from the primer cup forward toward the anvil that is inside the battery cup.

Super Sizer

Another way, which I have never had to try out, would be to get the matching gauge shotgun shell chamber checking tool - it's a cylinder with ID same as the nominal chamber opening. UniqueTek carries one for 12 gauge. Place the round base down on a piece of clean leather. Tap the cylinder checker down with a rubber or plastic mallet so the oversize round is fully inside the loaded-round checker, which will do the proper amount of resizing. And without putting pressure on the primer itself. Push round back out with a wood dowel.

One of a couple of Uniquetek's loaded round checkers

Oh, but .410 may be a little tough to find.

good luck, garrisonjoe

 

[garrisonjoe]

Keeping a loaded shell checker around is really useful, especially if you are feeding SA or pump guns where you need the shell to chamber easily. I've got a couple of them for 12 gauge, and always worth a check when having any feed problems or you scrounge hulls.

good luck, garrisonjoe