Need help with this cases' problem!.

[Nordeste]

Hi all:

I was wondering whether to post this on the handloading&reloading section, but this is about factory ammo, so I though it might be better posted here. If the mods think it belongs there, please do go ahead moving it.

Yesterday at the range, my shooting buddy noticed that my spent cases had the primers with a small bulge on them, just around the dent that the firing pin makes. He handloads his ammo (I still don't) and uses (until I start handloading) my spent cases.

In each and every case, it's factory ammo. Brands used are:

- Fiocchi 115gr FMJ, NATO spec. The one we get issued at work. Pretty hot ammo.

- Magtech 124gr FMJ. The regular stuff, not +P. The one I get at a reasonable price and the one I usually train with.

- Remington 115 gr FMJ. Also regular stuff, not +P.

- Santa Bárbara 115 FMJ NATO spec. This ammo was from the old times, when Santa Bárbara was still a Government company, before General Dynamics purchased it. Pretty hot too, even hotter than the Fiocchi.

We shot all this ammo and noticed this happening with each and every round fired. We shot the same ammo (the four types) in his Walther P99 and nothing of this happened. The cases showed the usual firing pin dent with nothing unusual around it.

As said, this guy handloads his ammo and his thought is that this is due to overpressure. I found it weird since it's factory ammo in each and every case, and only happened with my pistol, which, BTW, is a Beretta 92FS. He said it might be a problem with my unit, but couldn't figure out what kind of problem.

Now the pics:



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If you need pics from my pistol, I have no problem in uploading some tomorrow morning, after I get her cleaned. It's bedtime here .

Inputs appreciated, and thanks in advance.

 

[SharkHat]

If the primers didn't bulge when fired from his gun, it doesn't sound like an overpressure to me.

If it was happening on all of the different brands out of your gun, I might suspect that it's just the primer material being displaced by a firm firing pin strike.

 

[243winxb]

The Beretta 92FS has(i think?) an INERTIA FIRING PIN, A type of firing-pin in which the forward movement is restrained until it receives the energy from a hammer blow. It is slightly recessed in the breech face before being struck by the hammer and is shorter in length than the housing in which it is contained. Upon hammer impact, it flies forward using only its own kinetic energy to fire the primer. After firing, the pin goes back into the channel. This lets the primer flow back in to the firing pin hole. Plus it looks like you hole may be on the larger side, or too big. But you are using HOT loads in the Nato ammo. I do not think its a problem.

 

[Nordeste]

Thanks, SharkHat. The primers have bulged, slightly, but as you can see in the pics, it's bulged around the primer's dent. If it was actually an overpressure, should the primer be more bulged?. Is it that what you mean?.

 

[Drail]

That looks like the primer cup is trying to flow back into the firing pin hole in the breechface. With the slide off the gun push the firing pin forward so that it extends through the hole. Can you see any space around the pin? Do you know if this gun has been worked on before? If someone changed out the firing pin it may be just under spec. Sometimes people will attempt to deburr around the firing pin hole which can leave a slight countersink which the primer cup will flow into. If you look at the breechface closely you should be able to see what's causing this. It's really not a big deal until it causes the fired case to stick to the breechface when the barrel links down. If the load is overpressure the primers will appear to be flattened with the outside radiused edgeof the cup pressed flat.

 

[243winxb]

SAAMI has a warning not to use 9mm NATO (Military) ammo in a firearm chambered for a 9mm Luger (Parabellum) http://www.saami.org/specifications_and_information/publications/download/SAAMI_ITEM_211-Unsafe_Arms_and_Ammunition_Combinations.pdf But i was thinking militay shot hotter machine gun ammo in theres. I remember the slide hitting people in the face, till a stop of some kind was made to contain the slide.

 

[243winxb]

Nato is Higher Pressure.

Link to info http://en.wikipedia.org/wiki/9%C3%9719mm_Parabellum

9 mm NATO variant





The 9 mm cartridge has been manufactured by, or for, more than 70 different countries and has become a standard pistol caliber for NATO and other military forces around the world. Its official nomenclature among NATO users is "9 mm NATO". The 9 mm NATO can be considered as an overpressure variant of the 9×19mm Parabellum that is defined by NATO standards.[25] The service pressure Pmax of the 9 mm NATO is rated at 252 MPa (36,500 psi) where C.I.P. rates the 9 mm Luger PTmax somewhat lower at 235 MPa (34,100 psi). The 315 MPa (45,700 psi) proofing test pressure used in the 9 mm NATO proof test however equals the proofing test pressure used in the 9 mm Luger C.I.P. proof test. While the NATO standards do not specify the type of bullet to be used, the Hague Convention of 1899 prohibits the use of expanding ammunition in warfare by signatories, and therefore 9 mm NATO ammunition uses FMJ "ball" bullets.

 

[Pumpkinheaver]

The brass fired in my P95 looks exactly like yours. Has since the day it was new.

 

[Nordeste]

Thanks for your inputs, gents.

Drail, I have just talked to another range buddy who's told me exactly what you said. This afternoon, when I disassemble and clean the pistol, I'll have a look at that. This pistol was issued to me brand new, no one but the factory had ever fired it, so if there's any gap there, it's a factory issue, and if it's nothing but a solid firing pin hit, that's good news!.

243winxb;

The 92FS is +P rated. NATO ammo is similar in pressure, as far as I know, to the +P loads. There are different NATO loadings so this may differ. This Fiocchi ammo is what we're issued at work and the pistols are supposed to handle it well. Despite that, I train with the Magtech for two reasons, one is price and availability, and the other is to preserve the weapon as much as I can. As I said, it's issued, therefore not my personal property but my Government's. I'm responsible for it and I'm aware that using heavy loads on a regular basis will wear the pistol's components sooner.

The problem with the slides hitting people in the face is gone long ago. It did happen, but apprently it had to do with some quite heavy loads used by the US military that the pistols wasn't designed for. Later on, Beretta added a catch to prevent that from happening. I trust my 92FS .

 

[rcmodel]

Nothing I can see in the photos indicate high pressure.

High pressure would flatten the primer clear to the edge of the primer pocket.

Yours are still rounded on the edge, just like they were before being fired.

So, perfectly normal pressure.

rc

 

[BCRider]

Gotta agree with rcmodel. The look to me more like there's a fairly big opening where the firing pin comes through and that they are just bulging around the pin and into that hole. The two on the left even have a ridge that I'd expect from being pushed into a sharp edged hole. It's almost like the round fired and the pressure pushed the firing pin back into the normal at rest position and the metal of the primer cup followed it.

I'll have to check brass from my own 92fs next time I shoot it for the same signs.

 

[cactus02]

you have a firing pin hole with a slight bevel . This is standard for barettas and not a problem. the barrel and slide move in the same direction (straight back) not a droping barrel as in Browning.the browning design cannot have a bevel or you would shave off the primer.

 

[Jim K]

How about checking headspace?

Jim

 

[Nordeste]

I have cleaned her today and had a look at the slide, where the firing pin is supposed to protrude. As said, the firing pin is inertial, so even though you push it from behind, you can just see the "tip" of it, it doesn't come completely out. And, as expected, there's some area around the "nose" of the pin that doesn't completely fill the gap in the firing pin channel.

So, question answered, all clear, and thank you very much.

 

[Miked7762]

I don't know, the hole for the firing pin would have to be relatively enormous to account for that much bulging. If possible can you please post a picture of the breech face?

I see you are in Spain. Just to double check, the pistol under scrutiny really is a 92 and not a 98?

 

[Nordeste]

No problem in posting a pic, of course. Thing is that she's at work, in my locker, and I'm at home, but work is close enough, so I'll get her tomorrow or day after and make the pics for you.

It's a 92FS .

 

[Fishslayer]

Very informative thread. I find those type of primers all the time in my range pickups. It looks just like photos I've seen of cratering. Even the Glock fired 9mm has a couple of raised areas around the firing pin dent.

Now I know what they are.