.308 vs 7.62 NATO

[DaveBob]

Once again. Can 7.62 NATO surplus be used in hunting rifles such as Remmington 700's - caliber .308?
I know there are some demensional differnces and pressure concerns. What about the reverse - 308 in say an M-1? Thanks.

[paintballmagnet]

Re: .308 vs 7.62 NATO

In some rifles such as the M1-A I'd be leery of using .308 since it is usually loaded to higher MV than 7.62X71, usually around 100 fps with a corresponding pressure increase. Many loading books have seperate specs for each. MY FALS have digested many rounds of both with no problems since they have the sometimes maligned adjustable gas ports. I simply open the exhaust port two positions for shooting .308, this allows the extra gas port pressure to be vented into the atmosphere, not into the action of my rifles. As for your bolt gun, shoot all of either you want, there will be no problem.

[Steve Marshall]

Re: .308 vs 7.62 NATO

There MAY be differences in the firearms as the accepted headspace MAY be longer in the military firearm. There are no dimensional differences in brass save that military brass tends to be heavier/thicker. The differences in pressure oft quoted is much ado about nothing. In essence, the now accepted way of checking pressure gives different pressures than the old. (piezo vs. copper). The actual acceptable pressures are tinily higher in commercial ammunition. Some claim that commercially loaded ammunition in the higher weight bullets can wreak havoc on an M1A, I can't address that as I have no facilities to check pressure curves vs. weight versus velocity, blah, blah, blah. But guess what? Neither do the naysayers. There IS a caution with Garands as to port pressures bending op-rods with the heavier bullets and slower powders.

[jefferson101]

Re: .308 vs 7.62 NATO

It depends on the rifle.

An FAL will eat anything. Just adjust the gas port accordingly. (I'd start with opening it up about two notches with .308, and go from there depending on the ammo. Depending on bullet weight and load, you may want to go three or four clicks on the gas port.)

The concern goes back to shooting heavy bullets in a 30-06, because the Garand was built to eat milspec ammo, and nothing but. Yes, you can bend the op-rod on a Garand with heavy bullets, or heavily loaded 150g ones. 2650 FPS or so is nominal for a 150g FMJ, and depart from there at your own risk.

But that's a 30-06. FAL's? No prob. Adjust the gas vent.

I don't have an M1-A, so I won't speak to them.

Bolt guns? Unless you are talking about a Spanish .308 Mauser, I wouldn't be concerned. The Spanish 7.62x51's are kind of like the early '03 Springfields. You got to be careful with them. Other than that, it don't much matter what breed of .308 or 7.62x51 you shoot in the rest, as long as you adjust accordingly.

[DaveBob]

Re: .308 vs 7.62 NATO

Thanks for the answers. Very helpful. My bolt action is a Remington Model Seven. Older model but shoots like a dream. Also have an Springfield M1-A which I haven't shot that much. What is the weight of the usual spec 7.62? More than 150gr?

[paintballmagnet]

Re: .308 vs 7.62 NATO

Nato spec bullet is usually 147 grains. U.S. military match used to use a 173 gr. bullet IIRC, if this is still so? Years ago I deer hunted quite a bit with an HK-91, since I had several thousand LC rounds laying around, I'd pull the FMJ, seat a 150 soft point and go. Was once told that linked 7.62 was not very accurate, perhaps not with the sealed FMJ, I had no problem shooting deer out to 300 yards with my soft point conversion cartridges.

[Mannlicher]

Re: .308 vs 7.62 NATO

I shoot a fair amount of Federal Classic SP 150 grain stuff in my iM1A rifles. I use it for deer and hog hunting.
Standard pressure load, with about the same weight bullet as NATO stuff.

[Longbow1]

Re: .308 vs 7.62 NATO

I have a Remington M770, .308 cal. I have tried shooting NATO surplus, it shoots ok but it will jam bolt so it has to be tapped out with a mallet (small rubber one), I did some research and it appears that the NATO 7.62/.308 produces higher pressures and expands the casing in the chamber and jams the bolt. Apparently the chamber in my M770 is a tighter fit than my M1-A. The M770 will shoot just about any civilian .308 round, no problem and the M1-A will shoot just about anything 7.62 NATO or .308. I cannot attest to any other brand of "civilian" rifle. I have also come to find out the dimensions of 7.62 NATO and .308 are slightly different, if my source is correct. Just my $ .02.

[TreverSlyFox]

Re: .308 vs 7.62 NATO

The concern goes back to shooting heavy bullets in a 30-06, because the Garand was built to eat milspec ammo, and nothing but. Yes, you can bend the op-rod on a Garand with heavy bullets, or heavily loaded 150g ones. 2650 FPS or so is nominal for a 150g FMJ, and depart from there at your own risk.

Sorry but that isn't the complete story with the M1 Garand. While loading more than 180 grain bullets is a No-No in an M1 Garand. The BIG story is the gas system and using the WRONG powder as the gas system is designed for a Medium Burn Rate powder like 4064 or 4895. The actual muzzle velocity of the bullet really doesn't have anything to do with the "Peak Gas Pressure" in the gas system that does the bending of the Op-rod. Modern Commercial ammunition powder generates well beyond M1 Garand peak gas pressure specs except for the M2 compatible Hornady ammo being produced for the M1.

Sorry for being picky but I've seen several nice Garands messed up because someone used modern 150 gr hunting ammo in them.