Originally Posted by Jim B in CO
Well, what do you mean by "properly expanded"? I run the expander die down just "enough". It expands the case mouth enough so I can easily insert the bullet about 1/16". I do that and seat the bullet the rest of the way using the seater die. This seems to maintain neck tension and increase the life of the brass. If I expanded the brass so much that it wouldn't chamber in a Glock, isn't it "overexpanded"?
I just ran a sample case through my reloader. When I expand a case, it is just enough for the bevel at the base of a lead bullet to seat inside the case mouth. The skirt of the bullet does not fit inside.
This expanded case does not fit a case gauge and it only fits half way down the chamber of my G21SF.
With my setup, the case is expanded from 0.468" to 0.473" or a mere 0.005". Dillon recommends 0.020" of expansion (page 17 of Super 1050 Manual)! That's a LOT! It abolutely wouldn't fit a chamber, even on a Glock!
Next time around, I may flare my cases another couple of thousandths.
It's true that you don't want to overwork the brass. In my case, it's also true that I don't want to shave lead off the bullet while I seat it. It would be even more important with plated bullets to not damage the plating.
I don't know how many reloads are possible with 9mm or .40 S&W brass. I do know that .45 brass lasts forever. Or at least so long that I am more likely to lose it than to have a case split.
I know first hand the difficulties that arise from not taper crimping far enough. Yesterday, I had a few rounds where the casemouth was noticeably oversized and every one of them failed to chamber in my Sig 1911. I should have tried them in my Sig P220 but I didn't think about it.