380 case is bulging

[Havicman]

I have some 380 Auto brass that I'm reloading. I am having a problem with the brass bulging when I try to expand it before putting the bullet in. The brass is empty while I'm doing this. About 5% of the cases do this. Does anybody have any idea what is causing this and how to avoid it? The normal one is on the left, the bulging one is on the right.


Thanks

 

[rcmodel]

Any chance it is Federal or FC brass?

Some newer Federal .380 brass has an inside step in it to prevent bullet set-back while feeding.
Looks like what you got.

Back the expander out far enough it isn't expanding the step, and it should be fine.

You don't need to bell much atall with jackleted bullets unless you failed to chamfer the case mouths first.

Or you are loading lead bullets.

If the latter, you will have to sort out the Federal brass.

rc

 

[exbrit49]

Sure looks to me like RC model is right on

Think you nailed it RC, I have never had it happen to me as my dies are able to get over that step. but you sure can feel it on some of the 45 colt rounds.

 

[ngnrd]

If you're using RCBS dies, you may want to contact them. When my 380 brass was doing that, they said that they would send me a different expander plug. I haven't gotten it yet, but they say it's on the way.

And, yes... they said it was because the brass manufacturers had begun putting a step in the 380 brass.

 

[gamestalker]

It almost looked to me like you accidentally mis took the seating die for the powder / belling die, and then buckled the cases because it was trying to crimp a case mouth. Don't knowif that is even possible, never done that.

GS

 

[Havicman]

I'm using mixed brass including Blazer, Federal, Speer and some others. The bulging isn't isolated to any one brand. I am using RCBS dies though. I may need to check about the RCBS dies that I am using. This doesn't happen to all of the brass that I expand either. It only seems to happen to 5 out of every 100 that I do. All of the brass had been fired at least once. I have also verified that the brass is marked for 380 and not any of the 9mm calibers. I did have some 9mm Mak in the mix, this was my first lesson in reloading for the 380. I just started reloading for the 380. Up until now the only pistol ammo that I've reloaded for is the 45ACP. No problems with that.

 

[ngnrd]

I got my replacement 380 expander plug in the mail today. The expander portion is definitely shorter than the one that originally came in the set. If the brass has a step in it, this should keep it from being an issue while flaring the mouth.

 

[cactus02]

I had a oversize expander in380. chucked it into a drill press and sanded it to slightly taper it . now I get good seating interference and am able to open it up enough to start all bullets.