slamfires, .308 surplus, and the PTR-91?


February 26, 2009, 11:10 PM
Recently I've bought a PTR-91 and a RCBS rockchucker. I've decided against getting a port buffer for my gun, which means that the brass will probably be too bad to reload, but I've also read enough stuff about slam fires with reloads in another thread for ARs on here recently, and about soft primers causing problems in military semi-autos, that I'm not even going to attempt to reload for my PTR or AR until I get highly skilled at reloading, which basically means never.

Just reading about slam fires with commercial ammo makes me nervous though. I've put 60 rounds of federal power shok through my PTR, and 200-300 of the cheap remington FMJ through my AR. I've still got 300-400 rounds of commercial ammo for my AR, and about 120 remington core lokts in .308. Is this kind of ammo alright to shoot in my guns? Does this kind of ammo use the soft primers?

I know .308 surplus has about dried up, but it can still be found a little bit cheaper than the soft points I've been buying at bi-mart, so regardless of whether or not the soft points are safe for a semi-auto, I still want to get some surplus ammo instead. What's the best (and cheapest, although cheap no longer applies to .308) surplus to get? Is there any that's bad and I need to stay away from?

I just got a german "sniper" scope for my PTR from cheaperthandirt. Assuming it's safe to keep shooting the remington core lokts, I'm hoping to sight it in with those tomorrow if I get the time. These are 150gr BTW. I noticed most surplus is about 147gr, so if I get my scope sighted in with the remingtons, will it still be fairly close with the surplus ammo?


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February 26, 2009, 11:27 PM
I'm particularly interested in the quality of the Portugese, German, and South African ammo, as those seem to be the cheapest and easiest to find.

February 26, 2009, 11:30 PM
Port, German MEN, and South African are the top of the surplus 308 game.

If you can find it, buy all you can get your hands on. It's getting more rare all the time.

And, if you are finding them cheap and easy to locate, share with the rest of us please :)

While any floating firing pin rifle can slam fire, it is very rare in the G3 design. Best way to avoid slam fires is to not drop a loose round in the chamber and then drop the bolt. Load rounds only from the magazines. I shoot commercial 308 in my PTR regularly. I've pulled a round out before firing now and then to look at the primer.... hardly a dent.

February 26, 2009, 11:31 PM
I'm particularly interested in the quality of the Portugese, German, and South African ammo, as those seem to be the cheapest and easiest to find.

All those are just fine surplus. If you find it for .50 cents a round or less buy it.

February 27, 2009, 12:41 AM
Another thing to note is that several companies make mil-spec primers. For instance CCI number 34 primers are made harder so they can be used to reload things like 7.62x51mm (the actual bullet the M14 fires, practically speaking it's a .308).

February 27, 2009, 07:07 AM
The PTR has a spring loaded firing pin. I've never had an issue even using Federal Match primers in my handloads.

What a great rifle.

Lloyd Smale
February 27, 2009, 07:36 AM
that gun isnt really designed for the pressure that comercial ammo is loaded too. Also commercial ammo uses softer brass and you risk having case seperations. If your going to use it make sure you buy yourself a broken case extractor as your going to eventually need it.

February 27, 2009, 08:42 AM
CCI offers Mil-Spec hard primers specifically for loading .308 and .223 semi auto military type rifles.
Make sure your primers are seated correctly and you shouldn't have a problem with slam fires, even when using standard type primers.

I use a Forster primer pocket reamer and a Lee Auto Prime hand priming tool and don't have any problems with high seated primers.

February 27, 2009, 09:45 AM
designed for the pressure that comercial ammo is loaded too

SAAMI .308 is 65,000 psi. NATO x51 is 50,000cup.

That is the SAME pressure, just different measuring methods.

What shooters need to be aware of is the headspacing. Headspacing on the extreme ends can cause problems.

Most of the experts recommend that you keep your headspacing within the SAAMI ranges even if you shoot x51 surplus ammo.

If your rifle headspaces near or worse than the SAAMI field reject you should shoot ONLY x51 ammo because of the stronger brass.

The Kuhnhausen book on the M14 goes into a very detailed explanation of all this. I have never found the writeup online though.

Also on the G3/PTR you need to keep an eye on the bolt gap. There are stories about the gap diminishing quickly, in just a few hundred rounds.
Hasn't happened to my rifle, or anyone I personally know, but there are enough posts on gun forums to make it worth watching. It's easy to check.

Great video over this, a must watch for a new PTR owner.

February 27, 2009, 11:00 AM
Rifles with free floating firing pins, particularly the M1 and M1a have had many reported slamfires with commerical primers. And incidentally, a few with military primers. Rifles also at risk is the AR (very few slamfires but they do happen) and the SKS, and the French MAS 49 series of automatic rifles.

Even though the M1911 has a rebounding, spring loaded firing pin, enough of these pistols had discharged after being dropped, that most versions are now being made with a firing pin block.

The great trouble with commercial primers is that they are more sensitive than military primers. Primer manufacturers don’t like to be blamed for the misfires that are caused by ill maintained civilian weapons. There are people out there firing 125 year old weapons, with 125 year old mainsprings. Some of these people are “coil cutters”, many don’t clean out the gunk from their firing pin channel, and they complain loudly about the awful ammunition that won’t ignite in their thunderstick.

It has to be someone's fault, and it certaintly can't be theirs. :barf:

So commercial manufacturers provide primers that go off with a minimum of effort. Primer manufacturers that don’t, like CCI, are roundly criticized on these forums.

Federal is particularly proud of making the most sensitive primers out there, and their primers are very popular with the revolver shooters who use reduced power mainsprings. Because nothing else will ignite in their revolvers.

Without actually having the ammunition specifications, it is impossible to know if a particular make of surplus ammunition was made with less sensitive primers. However it is very likely. The military buys ammunition suitable for use in military weapons. Some of these weapons operate at extreme high cycle rates, the ignition systems have lots of reserve energy, so the military can use, and sometimes must use, less sensitive primers. I cannot imagine the death and destruction that would occur if the Chinese issued SKS ammo to their troops that had primers as sensitive as our commercial primers. Chinese SKS carbines have a free floating firing pin, and there are plenty of reports of these things slamfiring. One report of a guy whose SKS went full auto and he lost control of it. Killed him.

As so far for your PTR. I read of only one account of a slamfire in a PTR, and the gentleman said he never had one again. The HK G3 design is particularly well designed. If that design slamfires through firing pin initiation, it will be in battery. Also, the firing pin is spring loaded. This is not by accident: it was delibrately put in the design to reduce the probability of a firing pin initiated slamfire. I suspect the gentleman who had a slamfire had debris on the bolt face. Or maybe a high primer.

Always keep your bolt face clean, keep your chamber clean, always check that the primers on your reloads are below the case head, and don’t worry about it.

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