Commercial vs Milsurp pressure

[J'hawker]

Which generates the greater pressure, military surplus or commercial ammo?  I'm particularly looking at 308/7.62 NATO although I don't think that would have any bearing.

[alsaqr]

i've fired many thousands of different 7.62mm military surplus rounds in my .308s.  One of them is a re-bored and re-chambered model 95 Mauser.  None of my .308 guns have ever had any problems with military surplus ammunition, except for some Venezuelan 7.62mm ammo that was meant for the MG-42 machine gun.   Got it from Cheaper Than Dirt.  It had some kind of varnished coating on the case that delayed extraction in the machine gun.  Fired one round of the stuff in my Remington Model 700.  Bolt lifted easily but i could not pull it back.   Had to put the butt on the ground and give the bolt the old M1 kick to get it to eject the case.   Gave the stuff to a guy who owns a G-3 rifle and it worked great. 

Your mileage may vary.   

[Mikey]

J'hawker:  you are talking about 3 different types of ammo, I believe.  Most milspec ammo that I am aware of usually runs in the 47K psi range.  Commercial ammo made to mil-spec should run the same.  Commercial ammo made for hunting purposes often runs a bit hotter and in the case of the 7.62x51/308 Winchester, some of the 308 hunting loads have run to the 60k psi range, whereas mil-spec runs lower. 

Recently (within recent memory, actually) there was an article in the Shotgun News which looked at this issue and just as importantly looked at mil-surp ammo pressures in some of the more popular mil-surp ammos, including the 7.62x51.  What they found was pretty interesting and that in some mil-surp ammo the pressures actually ran higher than normal, due in part to powder degradation, and caused some rifles problems.

Heck, I would have thought it would mean lower pressured rounds as a result but apparently this is not always the case.

Are you concerned about using mil-surp ammo in a specific rifle?  This issue has surfaced before with some folk who shoot 7.62 mil-surp in rifles just like that mentioned by alsaqr and, I believe the responses and answers to their questions have resolved their concerns.  HTH.  Mikey.

[Aardvark]

Most .308Win ammo operates at 57k to 60k lbs.pressure in the chamber..Most 7.62Nato operates at 47k to 50k.

[jgalar]

When I am at a range I can usually tell who is shooting surplus ammo by the sound.
Bang, pop, Bang, KABOOM, Bang, pop....
You can't tell when you are shooting it, but others around you may be able to hear the difference in pressure/power that the surplus rounds are generating.
There is a reason the ammo is sold off as surplus......I won't use the cr@p in my guns.

[J'hawker]

I asked because a lot of guys I know have reported extraction problems with milsurp ammo in a variety of rifles and have blamed it on higher pressures.  I have a bunch of Argentine milsurp ammo (1950s) and a fair amount of Winchester commercial 7.62 NATO stuff left over from when I competed in Military Surplus rifle matches.  I used to shoot them through a Ishapore Enfield 2A1 and didn't have a problem, but there just isn't much rifling left in that old war horse and I've since retired it with honors.  Besides, those tiny sights are just getting too small to see clearly.  I hate it when a rifle gets old like that.

I was thinking about picking up another rifle just to shoot the ammo.  One of the possible acquisitions was a Savage 99, but those rifles have a rear lockup bolt which might magnify any pressure issues that might arise.  I've been cautioned by Savage fans that these probably wouldn't be a good match.  I'm just not sure I want another bolt action and the Browning 81 seems to be bit much for this project. 

[1911crazy]

Most .308Win ammo operates at 57k to 60k lbs.pressure in the chamber..Most 7.62Nato operates at 47k to 50k.

And the spanish 308 for the older spanish mausers was only around 40k psi.  You shouldn't shoot the newer commercial 308win ammo in the older spanish mausers they weren't made for the higher pressure.  I believe there is a warning about this at the Samco site were they sell the spanish 308 mausers.

With the new Russian Izhmash saiga's in 308 they can shoot either round the 308nato or the 308win ammo but were limited to staying under 168gr bullet with the 308win ammo.  It can't handle the larger heavier bullets from what i have heard.  I shoot only 150gr bullets with my 308 saiga's since there is no gas adjustment.  The lighter bullets move faster out of the breech over the heavier slower moving bullets thus the heavier slower moving bullets have a higher breech pressure at a longer peak time too. The lighter weight bullets move faster and have a much lower breech pressure and a shorter peak time. This can be a big problem in the semi auto's that aren't adjustable in the gas system. We learned all about that with the egyptian hakim's we must adjust the gas valve to the ammo were shooting and each ammo is differenmt so we must readjust it again everytime we change brands of ammo. The other semi's with adjustable gas systems are no different too they need to be adjusted correctly too.

Besafe know what your gun can shoot safely, besafe...........all these guns have different limits....

The worst batch of surplus ammo was the first batch of the indian 308 it goes pop, bang and them some won't cycle the semi auto.  They have found the powder charge to be all over the place and some were even overloaded too.  The new indian stuff is suppose to be better but i won't buy anymore of it.  With the 8mm surplus the yugo,  the equadorian, the turk all the rounds seem to be pretty equal.  The chinese norinco ammo seems to be a high quality ammo too in 7,62x39 and in 45acp it was good accurate stuff.

[corbanzo]

I'm in agreement with jgalar, surplus ammo is meant for surplus guns.  I know that I am loading my rounds a to a lot higher pressures than milsurp ammo is going.  Most production ammo nowadays is going to be loaded to the top end of things as people are going to buy by fps right after bullet sellection, especially with the number of ballistics comparison tools available on the web now.