Military 7.62 vs. Comm. .308 in Rem 700 ?

[Glennster]

I was told that the pressures in Military 7.62x51 ammo is too high for my Remington 700, but fine for my M1A. The guy told me I might damage the rifle if I use anything other than the regular factory/commercial .308 ammo.

Is this true???

AND, if it's true for the 700 in .308, is it also true that I should not use the military ammo for my 700 in .223???

THANKS for any help!!!

[Leftoverdj]

Be big news to the Marines who use Remington 700s as sniper rifles. If anything, the problem would be the other way around. Handloaded ammunition with very slow powders would change the pressure curve and damage an MIA over time.

Folks talk a lot of trash. Most of it don't mean nothing.

[Monkey]

I recall fondly how a couple of buddies and I took a bag of "extra" .308 (7.62 Nato, stripped from belts) out to the scrap yard, downrange Ft. Carson, Colorado.

We had my buddy's .308 bolt action, can't remember if it was a 700 Rem. or a 70 Win. We spent the afternoon seeing how good the armor plating was on an old APC in the yard (it was pretty good BTW.)

This was back in the late '80's. Not sure what kind of load that 7.62 was, but I know for sure it was meant for the M60. Look at any surpluss ammo catalog. They all have military 7.62 for sale. There aren't that many M1A's out there to fire it all. Heck, even the local Dunham's store has it by the case.

I've never heard of anyone damaging their bolt action by firing military grade ammo.

On the other hand, I don't (yet) have a .308, so please take what I say with a grain of salt, I could be wrong.

[Kayser]

I didn't damage mine, but I tried a box or so of a friend's milsurp and each and every round sealed -really- tight against the chamber. So tight in fact, that I had to really muscle open the bolt. After around 6-8 rounds of that, I didn't really feel like potentially shredding my chamber.

I've always heard that the real difference between the two calibers is the thickness of the brass used (the 7.62 tends to be thicker) so it can be unhappy inside of a chamber designed for brass of different thickness (when the round goes off, the brass briefly fireforms to the chamber).

This was some sort of random imported milsurp, so I suppose your mileage may vary.

[Dave R]

FWIW, I shoot 7.62 NATO in my Rem 700 all the time. No troubles. Not quite as accurate as handloads, but never any problem with pressures.

In Speer No 13 reloading manual, it treats .308 and 7.62 NATO essentially the same, with a warning to back off the load slightyl if using thicker milsurp brass.

[RJay]

Glenster, Your dealer is blowing smoke, factory .308 is loaded to a higher pressure than military 7.62 ( ( Bolt Action Rifles by de Hass and van Zoll, also Cartridges of the world 10 Edition). The caution is the other way. Be carefull of using factory .308s in some of the old converted Miltary rifles.

[Harry Bonar]

Dear Shooters:
I usually spend my time on the smitty but would like to comment here.
I've read and heard about this controversy for some time. Headspace gauges, pressure, etc. I've used 308 and 7.62X51 interchangeably and had no trouble.
I think the difference in gauges is under a thou' and pressure is within normal limits. Most loading manuals do not differenciate between the two so I think it's much ado about nothing!
Harry B.

[Glennster]

THANK YOU to all who help clear up things like this, they may seem simple and obvious to you, but are troubling to those of us that are on the front end of the learning curve.
Much appreciated ! ! !
Glenn

[cma g21]

I've never had a problem using 7.62 NATO in my Rem 600, Rem 7600, or H&R Handi Rifle.

.308 Winchester in a 7.62 NATO rifle may not be a good idea.

http://www.thegunzone.com/30cal.html

http://www.surplusrifle.com/shooting...nato/index.asp

[beenthere]

Read those articles. While you are probably ok using 7.62 in a .308 (If they chamber properly), you may not want to use .308 in a 7.62.

[joneb]

more info ; http://www.6mmbr.com/308Win.html

[Leftoverdj]

You folks are reading too much and shooting too little.

I like to read as well as the next guy, but I know better than to put much stock in anything written by folks who don't know about the two different pressure scales or the Spanish 7.62 CETME chambering for the converted 93 Mausers.

[Unclenick]

I wish it worked out that neat and simple and that a general rule of thumb could be applied, but I'm afraid Murphy has his foot solidly in this one. I too have had some 7.62 NATO (Portugese) rounds too hot even for the M1A: seriously flattened primers and some badly torn-up rims resulted. I still have it and still don't shoot it. The main problem is pretty well described at the crufler.com web site. It is that the 7.62 NATO was the first ever attempt to standardize a cartridge for an internatioinal alliance and that first attempt didn't work out perfectly. The stuff that comes from different countires can vary more than you'd like to believe in terms of performance.

I have seen some pretty flat primers on some old Lake City M118 (not the newer M118 LR, with the Sierra 175 gr. MK, but with the old 172 gr. FMJ BT), but I have never seen an American-made NATO round that didn't fire safely in everything. In foreign-made lots I have seen everything from the Portugese high pressure rounds I mentioned above, to stuff so flat that it wouldn't even cycle my M1A reliably.

I am exerpting the conclusion from actual measurement data of 7.62 NATO cartridges from a large number of countries of origin posted on Crufler.com below, because I think offers sage advice from a safety standpoint.

Originally Posted by crufler

CONCLUSION

The 7.62mm NATO cartridge, as produced by both NATO alliance members and other nations whose armies adopted weapons chambered for the round, displays a surprising degree of dimensional uniformity. Average case and projectile dimensions are nearly identical across the measured samples. Just as striking, however, are the variations in projectile weights and powder charges. Powder charge variations average in excess of three grains, and in some cases varied as much as ten grains. Bullet weights demonstrated similar extreme variations, with a low of 122 grains and a high of 186 grains.

Evident then is an emphasis on interoperability rather than interchangeability. 7.62mm NATO cartridges from various sources can be expected to chamber and fire in a wide variety of weapons. What they cannot and should not be expected to provide is a similar level of ballistic performance. . .

. . . What of the collector and shooter, using whatever bargain priced 7.62mm NATO ammunition is available? There are a couple rules that can be gleaned:

Nations do not surplus ammunition they need. Surplus ammunition is either old, unreliable, or obsolete, and merits a degree of caution in use.

Fortunately, most of the 7.62mm NATO ammunition on the market has been surplused due to obsolescence.

The terms "NATO standard" or "NATO spec" generally speak to cartridge dimensions, and not to ballistics {either interior or exterior}. . .

Caveat emptor.

Nick

[44 AMP]

US milspec for ball in 7.62Nato is 150gr @ 2750 +/- 30 fps.

US factory ammo (Rem, Win, etc) lists the 150gr @ 2860fps.

Which one do you think would be "hotter"?

[Unclenick]

Figure about 25 fps per inch of additional barrel length. Shoot the military round in a 22" M14 barrel, and get 2750 fps. Put the same round in a 26" sporter barrel and get 2850 fps. This matches SAMMI well. Their standard pressure/velocity barrel for .308 is 24" long. They call for a 150 grain bullet to go 2800 fps from that barrel. Just what the military round would do in a 2" longer barrel; SAMMI just allows higher pressure limits to get the bullet moving that fast. About 46 grains of IMR 4320 satisfies both criteria in a military size case. Same 50,000 PSI by Piezo transducer. I doubt the liability-conscious mass ammo makers load to full SAMMI max.

Nick