Finnished Rounds Measure .473"

[Bob McGee]

In measuring my finisher .45 acp rounds I find that they measure .473" as compared to .469" - .470" for factory Winchester. I am using a .452 lead hard cast bullet, loaded on an XL 650 Dillon, with Winchester cases. Cases are well used maybe 20 reloads with mild charges of Bullseye and tight group. I am starting to find about 1/3 of my reloads do not want to just drop into a case gage without a little pressure. this is some thing new. any suggestions?

[revchuck]

Bob - .473" is the dimension shown in the illustration in my Speer #13 manual, so it shouldn't be a problem. You can always taper crimp them a little more to reduce the case mouth, but you didn't say where the rounds were hanging up. If it's somewhere past the case mouth, the additional taper crimp won't help.

The fit that you really have to worry about is your barrel's chamber. Try using that as a case gauge. If they all drop in without any problems, you're good to go. If not, then you need to look some more.

[Gun Geek]

From your post it sounds like this problem just started happening - so something has changed?

Make sure the gage is clean both rust and oil will cause problems. Make sure your sizing die is all the way down (just kiss the shell plate)

Do they go partially in and then stop or do they drag as soon as you put them in the gage?

Could be a bulge - this isn't glock brass is it?

I crimp mine down to .470 and use a Lee FCD - no problems chambering in 10K rounds.

[pskys2]

As you shoot .45acp brass it will shorten.

New is usually .898, 1x goes .892, X+ .885 (sometimes less).

The shorter it gets the further from the taper crimp.

The taper crimp usually works best at .470 or less, can start having problems under .465.

Try setting your die to give you .470 on the old brass, then run a new case through and it will probably be about .468. Both should then work fine.

Lead is more forgiving as long as you bell the case mouth enough (which it doesn't sound like). Try belling the case mouth on the older brass just enough to not shave lead, then run a new case through and it shouldn't bell so much that it won't fit into the next station.

Jacketed bullets can be crimped too much and they will get loose in the case. Again .468-.470 seems to be best.