9mm brass bulging during reloading

[West Chester]

On the left is a 124gr Montana Gold bullet and on the right is a .356 sized 147gr lead bullet.

I load to an OAL of 1.065" for the lead, slightly longer than recommended and the brass starts to bulge below where the bullet seats. out of 50 WIN headstamp all showed some bulge and 1 did not fit in a 9mm case gauge. 10/10 9mm PARA headstamp did not fit in the case gauge. No bulge is present on the 124gr bullet.

Can someone help me figure out why this bulge occurs and how to fix it?

[762xIan]

I have noticed this also, a little bulge is normal. However, there are a few things you should be aware of before you proceed.

The deeper you seat the bullet, the more bulge there is going to be because the brass is thin at the case mouth and gets thicker down toward the case head. So, maybe not seating so deep will help diminish that bulge a little.

Maybe the most important thing to be aware of when loading small pistol cases like the 9mm is that seating deeply greatly diminishes the volume within the case. What that means is that pressure will rise, and the rise tends to be much more dramatic in a very small case.

I would seat that bullet as far out as possible, giving consideration to whether the reloaded cartridge fits in the chamber, the magazine and feeds reliably in the pistol.

Good thing you had the case gauge to check your rounds.

Here is a link to a previous discussion we had here on this issue: http://forum.pafoa.org/ammunition-re...ass-shape.html

Hope this helps.

[Guns N'at]

On the left is a 124gr Montana Gold bullet and on the right is a .356 sized 147gr lead bullet.

I load to an OAL of 1.065" for the lead, slightly longer than recommended and the brass starts to bulge below where the bullet seats. out of 50 WIN headstamp all showed some bulge and 1 did not fit in a 9mm case gauge. 10/10 9mm PARA headstamp did not fit in the case gauge. No bulge is present on the 124gr bullet.

Can someone help me figure out why this bulge occurs and how to fix it?

Deeper seating/more bullet shank of a slightly "fatter" bullet further in the case which tapers pretty well the deeper you go... What you are seeing is nothing, and something I like to see, as it assures very high case tension, which is very nice to help prevent bullet setback. If it chambers easily, has proper mouth dimensions (taper crimp setting), and the bulge is symmetrical, their is no problem.

Get rid of it?... Might not be able to (would not anyways) with that bullet. Case wall thickness/taper can and does vary by brand and lot, plus the dimensions of your sizing die might really resize the case, and what you have is what you get. Might also play with lengthening the OAL if possible, using your barrel and magazines as your guide. Other item to try if really wanting to is a Lee factory crimp die, and see what it does. I have no use for the things, as I don't want any post sizing going on, potentially ruining the very bullet sizing I choose.

Here are some .3575" 140 grain TC bullets I loaded today on the left in thick walled brass (CBC/Magtech), using my super maximal sizing Dillon dies, and they display plenty-o-bulging in a uniform manner. My pistols have generous chamber and groove diameters, and the fit just fine.



If they chamber in your particular pistols barrel after testing, cosmetics would be the only thing "wrong" with them at worst. Good luck.

[WVBob]

It's normal when loading the 147 gr in a 9MM. While you can use them in 9MM the 147 gr bullet works best in a .38 Super. Also, your dies may be bring the case down to a .355 size and your loading a .356 bullet. Normal things. Try loading a 130 gr bullet and see what you get.

[Arrdy]

Trim your cases to the same OAL then reset your crimp. I can see you're using a taper crimp, but it's a bit much also note the difference in the case length ... IMO

[MaDuece]

It's normal when loading the 147 gr in a 9MM. While you can use them in 9MM the 147 gr bullet works best in a .38 Super. Also, your dies may be bring the case down to a .355 size and your loading a .356 bullet. Normal things. Try loading a 130 gr bullet and see what you get.

Most likely the bullet you are running is a flat based bullet designed for 38 super.

Hornady was one of the first to realize the bulged brass problem when using 147gr bullets in 9mm Luger and they designed thiers with a boat tail base to help eliminate that problem. Thats also why its recommended that you run a longer OAL with 147gr jacketed (I noticed you are using lead) with some recommending as high as 1.165 OAL with jacketed bullets.

The only other possability is if your crimp is way too tight and is actually crushing the case but from the pics you posted that doesn't appear to be the case. Usually when the crimp is set that tight on lead bullets it will actually crimp the case mouth into the bullet to the point of being flush. That would be definate bad juju due to the fact the 9mm headspaces on the case mouth.

[West Chester]

The 147gr Lead bullets that I am using are these
http://www.kingshooters.com/147gr-rnfp-p-25541.html



When loading 124gr Montana gold HP's I get no bulge but the 147gr lead it bulges bad and some do not fit in my case gauge.

I will try running a longer OAL and report back

[L T C]

[QUOTE=West Chester;1556570]The 147gr Lead bullets that I am using are these
http://www.kingshooters.com/147gr-rnfp-p-25541.html




FWIW, I use Roger's 125g LRN 9mm's with no problems and they shoot great out of my pistols and carbine.

If you get no luck with your 147's I think Kings will take back what you haven't used...

Also, those case gauges are good to have. I run every round I load for through one before it gets to the ammo box.

Better to weed out a problem round at the bench! They have saved me problems at the range.

L T C

[glockonr]

I know this is an old thread but I wanted to get this out there. I think I have solved the bullet bulge issue. Using a lee resizing die and a lee final sizing die.
You will need to find a decapping pin that has a longer stem than the standard 9mm die.

I'm loading on a 20 year old Dillion 1050. I backed out my resizing die and then began to thread it back in a turn at a time until it would grip the bullet after being belled. Right now the lee resizing die is .125 off of the shell plate. From there it went through the Lee final size die and revealed virtually no bullet bulge. You can adjust the sizing die a half turn until you began to see the bullet bulge start to show. You may need to do several adjustments until you get the look you want and feel you have plenty of bullet grip. I have been dropping then in a model 19 Glock barrel and they fall just like a new factory round and the bullet appears to be tight. This should also work on other cartridges like the 45 and the 40.

I would like to hear from someone on this at glockonr19@yahoo.com

[cephas]

glockonr, first post, welcome. If I'm understanding this right, and you're talking about a lead bullet, you're probably resizing it with your method. Depending on your groove diameter it may not be a good thing, particularly in a Glock. I'd keep a close eye out for leading in the barrel.