orygunmike
orygunmike
3 posts
Joined December 2007

Seated Bullet Causes Bulged Case

Hello.
I have been reloading fairly successfully with my 550B for 9 years. Over the past year I have encountered issues when loading Montana Gold 9mm/124gr JHP. In perhaps 10% of loaded cartridges, the case is bulged, causing difficult with the gun going into full battery.

It appears that that bottom edge of the bullet, as it is being seated into place, is pushing outward against the case side, causing the bulge. I have tried to be extra careful about ensuring that the bullet is sitting horizontally (and not tipped) before seating, but I have never had to worry about this with other bullets.

Thoughts?
dillon
Administrator
dillon
2,945 posts
Joined July 2007

RE: Seated Bullet Causes Bulged Case

(mm is a tapered case, so it is normal to see the base of the bullet outline on the outside of the case. It should be visible all the way around, however. If you only see one side, then loosen all of the die lock rings, have cases/cartridges in all 4 stations, and pull the handle down. With the handle down, tighten all of the die lock rings. This ensures that the dies are straight in the toolhead, and that the bullet is seated straight.
exfed2002
exfed2002
7 posts
Joined February 2011

RE: Seated Bullet Causes Bulged Case

This is very timely.

I have the same problem with my 550B and 9MM.

I've been loading them for a long time, and my SIG 320 swallows them without problems.

I just got a Glock 43, and it is having problems with maybe 10% for the rounds not plonking freely and not wanting to go completely into battery. All of the bad cartridges have bullet bulges on only one side of the case, and increasing the taper crimp helps in only some of the cases.'

I'll try this, and maybe I won't have to plonk test all of my reloads into SIG only and all others boxes.
exfed2002
exfed2002
7 posts
Joined February 2011

RE: Seated Bullet Causes Bulged Case

I am so glad I found this post.

I found the problem. I had the charging die set to give me a "no problem" bell for bullet seating, but in doing plonk tests, I found that if I reduced the bell just a hair, the problems disappeared and all rounds plonked in and fell out freely! I suspect the slightly larger bell allowed the bullets to seat unevenly, and that would give me the ring around only part of the case instead of no ring or a uniform ring. This distorted the case enough that the taper crimp couldn't correct it and the Glock chamber would reject it while the SIG would swallow it whole.

I tested unsized fired brass and resized fired brass before I checked the charging bell size, and both would plonk in and out.
charleshutcheson
charleshutcheson
1 post
Joined December 2017

RE: Seated Bullet Causes Bulged Case

i have failed to get my 550 powder charger to be consistent. i took it upon myself to test each and every powder charge since i'm starting to load rifle rounds of which ive never done before. i cant seem to get the powder bar adjusted to give same volume of powder no mater what i do. any advise
Bucolic_Buffalo
Bucolic_Buffalo
62 posts
Joined June 2016

RE: Seated Bullet Causes Bulged Case

Hi Charles, Your problem is not what this thread is about. But you still needs answers.

I would look through the posts and you should find some specific recommendations. Most having to do with static electricity and solving that with the use of dryer sheets. I do not have that difficulty here. But you might try giving the measure a wipe with a dryer sheet. Even hanging a strip down in the measure to try and transfer static charges to the metal part.

What has worked for me. Is slowing down. Giving the powder time to actually move into the chamber of the thrower. Some of these powders move slowly. Especially stick. Combine this with a static problem and it really is a pain.

Good luck.
alaska_guy
alaska_guy
6 posts
Joined January 2018

RE: Seated Bullet Causes Bulged Case

Charles, also some powders just meter better than others. If your using unique, expect the charges to be off by .02 or so. If you use a fine powder like silhoutte you wont run into the powder charge difference issue. Hopefully that helps.
pegrannan@gmail.com
pegrannan@gmail.c...
8 posts
Joined July 2010

RE: Seated Bullet Causes Bulged Case

I have a similar problem but not on all bullets.

I have a 550C/9mm(Dillon Dies)/Missouri Coated 124glrn bullets and not all rounds pass the case gauge.

So my last attempt I ran 100 + rounds through Resize and decapping only. I picked out 80 that all passed the 9mm case gauge test. After loading those 80 rounds I had 2 or 3 that did not pass the case gauge check as I was expecting them to. Is that normal? I've been playing with the case bell but maybe can't seem to get it just right? I guess I'm not sure how much bell is really needed. At one point it was removing some of the coating which I figured was not enough.
Does anyone have any suggestions or can recommend what is the best way to determine how much case bell is needed?