Jump to content
Brian Enos's Forums... Maku mozo!

Name fore a bulge in the bottom of a case


Recommended Posts

When I started reloading 9mm on XL650 i was getting a small bulge in the bottom of my brass. I called Dillon and he went through the whole press settings with me and then had a run 1 case through each station to see where the bulge was forming. We found that it was in the fourth station when I was seating a bullet. as I seated the bullet I could see a slight bulge form. He had me back off of the seating depth by a 1/4 of a turn on the seating die until it did not bulge. The OAL was fine and the bullets fed fine.

My question is what is the other names for the bulge in the bottom of the case. It was not a technical name. It did prevent me from clambering the bullets. After that I never had the problem with any caliber I loaded.

Thanks for the Help!!!


Link to comment
Share on other sites

I've had the same thing happen loading 38/357..... The seating die will push down on the case if its set too deep. I've actually had some "wrinkle" till I got the crimp right. I'll try and find a few of them and post some pics...... BTW, this was on a 550. If I remember correctly, I didn't feel anything out of the ordinary loading this round. There were several more like it, till I got the dies set up correctly...





Edited by GrumpyOne
Link to comment
Share on other sites

How was the seating die causing a bulge in the brass?

Because you're using a seat / crimp die. The die body is adjusted to control the crimp, the seating stem controls the seating depth. Screw the die body in too deep and it tries to crimp (prematurely) as the case goes in. If you're doing a seperate seat and crimp the die body in the seat station has to be adjusted to NOT crimp.

With the ram up and a sized case in the seating station, screw down the seat die body, with the seating stem backed way out, until you feel it contact the case. Back it out a quarter or half turn and lock it down. Now set your seating depth with the seating stem. You should be good to go. The body is "up" enough to not crimp.

With the seat / crimp die screwed in too far you're crimping the case to the bullet prematurely and pushing the base of the case up while it's mouth is locked (crimped) to the bullet. The press has enough mechanical advantage (leverage) to let you really wad up the case.

Edited by Tom E
Link to comment
Share on other sites

It wasn't much, IIRC.... I tossed the rest, but kept that one....Ugly, ain't it? I think it had a bit to do with the 357 case being such a long case, and the seat die almost acting as a crimp die as well. Once the bullet was seated to the max depth of the die, and the press still had some movement before the other dies bottomed out on the shell plate, it simply "wrinkled" the case. And, the crimp is actually ok (roll crimp). So, in essense, it crimped the bullet, and since it was crimped before the dies bottomed out, it just wrinkled the case, as the bullet could not slide down into the case any further because of the crimp.

Link to comment
Share on other sites

Maybe the cases are not being expanded enough, so as the bullet is seated 'past' the portion where its expanded, starts to crush the case?

This is one of the differences on the 1050, case expanding and flaring are separate stations, and it seems like doing this in different operations really allows both to work better. This especially comes in true when you're using lead bullets (since their a thou larger)

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...