What caused this bulge in the 9mm Luger shell case?

[jim147]

Load them and let us know. I think you will be fine. I have been wrong once.

[oldblinddog]

I’ve had bulges like that in a Marlin 1894 .45 Colt. Bought new in the 80’s. I returned the rifle.

[FLINTNFIRE]

Those who subscribe to the bulge busting , should keep them for their own use , but invariably someone sells them , I have had a bulge busted case split , when I find them I throw in the scrap where any compromised case should be put .

[W.R.Buchanan]

Those cases were NOT fired in a Glock! The Glock Case Bulge looks nothing like that and also it was only done to .40 S&W cases,,, Not 9MM's ! IF anything those two cases look like they were "stove pipes" that got caught between the slide and the back of the barrel. IE: Type 2 Malfunctions.

You don't debulge 9MM's anyway as the case is tapered, and the web of the case extends much farther forward than it did on the early Federal .40 S&W brass. 9MM brass is much stronger than .40S&W brass anyway.

Do not load Federal .40 S&W Brass with headstamps of "FC" or "FC10" as these two series of Brass were where all the problems with Kabooms came from.. Most of this brass has gone to the scrap heap many years ago but some still lurk in the shadows waiting to blow you up, so you kind of have to look at your brass before you load it.

Also all Glocks from 3rd Gen on had the chambers changed so the intersection of the feed ramp and chamber was much smaller so they didn't do the Bulge, and also all ammo makers corrected the design on .40 S&W brass to extend the web of the case much higher so the area of the case that coincided with the feed ramp was beefed up.

Neither of my Gen 3 guns (G35 2007) and (G23 2015) do it. Fired thousands of rounds of both factory and Reloads thru both guns with no issues whatsoever. It is also good policy to NOT HOTROD the 40 S&W round as it already operates at 35,000 psi which is not too forgiving of loading errors. There is absolutely nothing to be gained in the real world by pushing this round. If you want HP ammo for SD go buy some. Hornady makes some good stuff at about $2 a shot.

This subject has been covered extensively over the years on this site and a search will bring up reams of info on it. I first commented on it in 2011 when I first came here, and said essentially the same thing as I wrote above.

Randy

[Outpost75]

Buchanan is correct. Smash and destroy to prevent reuse. Otherwise setting yourself up for Kaboom!

[tankgunner59]

I have bulge busted 40 S&W cases with the Glock bulge and the signature Glock firing pin indent with no problems. But to my understanding 9mm with it's distinctive taper shouldn't be ran through a bulge buster, I would pitch them and move on especially with that dent from what looks like the slide. Just my .02

[reloader28]

You have to use a 9mm Makarov die to de bulge 9mm Luger and yes it does work

[Soundguy]

Dusty has it. Fired in a Glock.

Don

yup.. glocked brass....

[farmbif]

good 9mm brass is too easy to find to load iffy shells, just throw them in the recycle bin and move on. my old gunsmith mentor would have probably said they came out of some cheap junk gun that aint worth fixing because sometimes there is no way to correct a bad design

[matrixcs]

I have seen this bulge when someone has taken a Dremel to the feed ramp in the barrel to get better feeding...One guy at my range managed to blow his gun apart by doing this mod...no support at the back of the case is not a good idea..

[kevin c]

I agree with WRBuchanan. I've shot mostly stock barreled Glocks for years, and have never seen a bulge in 9mm, only 40 S&W, and not my Gen 3 40's.

If those cases are marked from an inadequately supported Glock chamber, the "smile" should be completely symmetric, should delineate the bulged area of the case (which was much more pronounced in the 40 cases I saw), and be aligned directly at the 6:00 position relative to the firing pin mark (which is rectangular with a central dimple in Glocks). If the pic shows all of the mark that can be seen in those two cases, I'd be inclined to think more of dings from hitting the ejection port than of unsupported chambers.

9mm as well as 40 S&W cases can have any bulges removed by using devices that roll the cases between specially ground plates that can do straight wall or tapered cases no problem. The devices wee originally designed with the "Glock bulge" in mind, even though that issue is rare these days. Now folks do it for chambering reliability. I have never heard of a catastrophic case failure from a case reconditioned this way.

[1006]

I am guessing it was fired in an open bolt fully automatic or in a blowback operated Carbine-could have been loaded hot with too slow a powder or could of had a week recoil spring. In either case, my guess is the bolt slid back just a little too soon, before the pressure dropped off.

Another possibility is a Glock scenario where a reduced recoil spring is combined with an increased power striker spring—as the trigger is pulled, the slide is pulled slightly aft, and the cartridge ignites slightly out of battery, at least that is the warning issued by LoneWolf with their extra power striker springs.

[Soundguy]

Hdn't thought about a subgun. guess it is possible.

PS.. a lee 9mm fcd 90860 will also debulge glocked and similar brass. it has a carbide sizer ring for ironing out overzealous crimp attempts.

[Old Caster]

To be sure, the cases need to be measured to see if they are actually bulged because to me it looks like the cases have hit something and put a dent in it. A possibility is a scope mount that hangs over the ejection area making the brass hit it. I have seen brass like this before and it was not bulged. Can you measure them and let us know what the facts are?

[David2011]

Bulged or not, I would be leery of the crease. It’s a head start on a failure point and I would not reload them for myself.

[Soundguy]

Could be ejection port contact.

[358429]

Without seeing close up, perfectly focused, zoomed in, excellent pictures from all angles, eliminating any

source of uncertainty as to the nature of why this brass has an unusual appearance

is a moot point.


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