Bulged Brass: What is Going On?

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Norinco45

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While scrounging some brass from the local shooting emporium I scooped these up. When inspecting the picked up brass at home I found about 10 cases bulged at the head. Micrometer shows the bulge at .030". I don't profess to know much about reloading but YOW!! this seems dangerous. The bulged cases showed a progressive increase so I suspect that someone was working up a load.

I am curious what was going on here. Is this the "Glock Bulge" I have heard about and is normal due to the unsupported case or is this a sign of a dangerous load?

This has impressed on me the need to inspect carefully any brass I pick up at the range!!!
 
Ramped

Looks like somebody needs to put a heavier recoil spring to retard opening just a tad; it looks like that brass began its extraction a bit earlier than needed and that bulge just above the case web corresponds to the relief of a ramped barrel.
There was sufficient remaining pressure to bulge the thinner brass.
Is there a firing pin wipe mark?
PP.
 
Norinco45 said:
Is this the "Glock Bulge" I have heard about and is normal due to the unsupported case or is this a sign of a dangerous load?
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Yes and Yes. Usually Glocks crap out brass that look a little like that, though not that extreme. Those look like hot reloads and should not be touched. If that's factory ammo, the dude that fired them has got a seriously flawed firearm.
**Only scrounge brass if you know its once fired factory stuff. Saving a few bucks will not be enough to buy new body parts.
Example some ranges (few) only allow you to fire factory ammo you purchased at their range... generally safe, but scrounging frowned upon. I'm not gonna name names. Or go to your local range after the cops have been there... they don't reload and only use factory ammo for legal reasons...

You can't know who abused brass how many times or how badly from looking at it. Well, unless it looks like the ones in your picture!
 
PerversPépère said:
Looks like somebody needs to put a heavier recoil spring to retard opening just a tad; it looks like that brass began its extraction a bit earlier than needed...PP.
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I don't wanna hijack this, but I disagree with PP. I'm no expert on the matter, but timing has more to do with slide weight and lockup design than recoil spring weight. Recoil springs are there to save the frame from battering itself to death, hence heavier springs for heavier loads. The bullet/pressure is long gone by the time the slide starts to move. If I'm not mistaken you can safely fire an autoloading pistol without a recoil spring.... it has less to do with true 'recoil' than 'reloading'.
Some Glocks are proven cabable to fire out of battery... ie a pull of the trigger will drop the firing pin without the slide having moved all the way closed. Some claim this is the main reason Glocks KFB more often that other types. A lite case of F.O.B. could cause those marks as well. Just a thought. If anyone can deny confirm my claim about recoil springs please let me know!
 
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Try any firearm without recoil spring and you will see that the slide is very easy to slide back. It help keep it forward.

Norinco45 Look at the firing pin mark, is it square? What is the caliber and are they all the same brand?

Square mark is Glock, .40 would be my pick since it's very high pressure and glock handle them very badly because of the chamber. (bulged brass).

If they are mismatched brand, probably reload.
 
Ramped and relieved

I should have added "perhaps too much relieved".
Some cam profiles too, can affect degree and rate of opening but a too enthusiastically relieved chamber edge makes bulging brass an everyday's routine...
PP.
 
Correct me if I'm wrong, but I believe that is .45 auto brass.

Regarding the firing O.O.B., Xds are capable of it too.:redface:
 
Firing Pin Mark

Thanks for all the replies. We seem to be playing CSI Guns!

303shooter


A bit more data for you experts. They are .45 ACP brass, a mixed bunch of Federal, WCC and RP. The firing pin mark is quite distinctive, above a normal circular pin indentation is a vertical "slot" at the 12 o'clock position and below the indentation at the 6 o'clock position is a lighter, horizontal rectangular mark. None of the primers seemed to my admittedly unexpert eye to have any of the typical compressed indications of an overcharged load.

By the way, taking good pictures of brass is harder than I thought!!!
 
Show a picture of the case head (that'll let us know if it was fired in a Glock, or something else); I've never seen a case fired in a Glock that was bulged like that.
 
on the other hand , if it were 9mm, i've seen new brass that looks like that after it's been through a sterling or a uzi c/a- typiclly the stuff i'd fire though the uzi would look like that , so i'd chuck her after a runthrough
 
Some folks like bashing Glocks for some reason.:mad:. Probably dont own one or have any experience with them;) . I have a few Glocks. in various calibers, and have been reloading them as well for years. I have never seen any bulging even the remotest bit similar to that:eek: . Either dude has a serious problem with his weapon or he's using some sort of auto fire weapon..
Now stop picking on poor Gaston's pride n joy:p
Cheers
dB:)
 
DaBear... I can't speak for everyone, but for me its not that I don't like Glocks, its that I don't like the attitude surrounding the whole "Glock PERFECTION" preachy crap. They are far from perfect... pro-Glockers generally don't like to admit that. I don't know of any other manufacturer that claims that crap... and that's why I refuse to own one.
Yet I know they are fine arms and have enjoyed shooting them. No one likes the blind unquestioning following Kool-aid gangster crap stuff. Okay, hijack over.... back to work.

Anyways, that firing pin impression does look a little Glocky at the top end, but the bottom is too round for a glock.
 
that's a pretty big boulge there...

.45acp is low pressure round (+p would would be 23,000psi, where 35,000psi is normal 9mm/40 preassure). I would have to go with a overcharge or the gun shooting out of battery...
 
Now that I've seen the picture - that's not a Glock mark. It's a normal firing pin mark followed by a drag mark, where the pin is still out as the brass ejects.

If you experiment with hot loads, you'll find that the hotter the load the bigger the drag mark - I assume because the more aggressive recoil holds the firing pin assembly forward a bit.

So, it's fairly hot loads from a generic 45 with a somewhat unsupported chamber. If the loads were really, really hot you'd see marks on the case head from the receiver face, which I don't (although the pic is blurred a bit). Call Grissom.
 
IM_Lugger said:
that's a pretty big boulge there...

.HAHAHA

I wonder if whoever reloaded those cases had the seating or the crimp die to low and crushed the base of the case? No wonder they didn't pick those ones up, hehe.
I shoot a Glock, and the firing pin mark in the primer is a little more simetrical than those pin markings. I agree call Gill Grisolm or even beter yet Kaly Ducaine in the Miami office.
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