7.62 ammunition questions.

[BPShunter]

Hi,
I know this is probably a noob question but I'm not very experienced with military calibers. What is the difference between the different types of 7.62 ammunition? There's the 7.62x39mm, 7.62x51mm, and the 7.62x54R. There's also a 7.62x25 Tokarev which is a pistol caliber but I'm not concerned with this one, just the rifle calibers. I do know that one of these is the equivalent to the .308 Winchester civilian caliber. I also know that one of these is used in the SKS and/or AK rifles. Can anyone clarify? Thanks.

[deanadell]

7.62 denotes the caliber of the projectile in millimeters
The next number indicates the length of the case in millimeters

The 7.62 x 51 is the NATO equivalent of the .308 cartridge
The 7.62 x 39 is the AK/SKS round
The 7.62 x 54R is the old Russiam Mossin Nagant round, still currently used in their sniper rifles.

There is a slight difference if I remember correctly, in that the Soviet rounds actually measured .311 instead of .308

[blancoman]

And last but not least the 7.62x63 or 30-06 as it is better known. And yes you are right the russian is .311

[30Cal]

Some people (and foreigners) refer to the 7.62mmNATO as "7.62x51". It's more or less interchangeable with .308Win depending on the chamber dimensions of the rifle.

Ty

[45reloader]

7.62mmNATO or "7.62x51" has thicker brass because of less chamber support in military guns.They are built to work under the dirtiest of conditions. Don't ever fire standard 308 Winchester ammo in a NATO chambered gun or you might have a big KaBoom.

7.62 is the diameter of the bullet.All the x25, x39 ,x51 is the overall length of the cartridge.

But these guys have already told you that.I just wanted to raise the post count.

[revjen45]

Does this mean firing .223 in a 5.56mm chamber will result in KB?

[Clayfish]

Don't ever fire standard 308 Winchester ammo in a NATO chambered gun or you might have a big KaBoom

It's the other way around. You shouldn't fire 7.62x51 in a tight .308 chamber. You also should not fire 5.56 in a tight .223 chamber. .308 is fine to fire in a 7.62x51 chamber.

[VUPDblue]

clayfish beat me to it...

[moose fat]

I just bought an Ishapore 2A in 7.62 and was visiting ParallaxBills "The Enfield Forum" http://p102.ezboard.com/bparallaxscu...firearmsforums getting knowledgable about my new old gun. There has been an ongoing debate on this topic. It is extremely relevent for shooting old mil-surps and I was lead to the following site.

http://www3.sympatico.ca/shooters/7_62vs308.htm
http://www.6mmbr.com/308Win.html
This last site the relevant info is near the bottom.

In a nut shell;
-.308 brass is thinner than 7.62...more gun powder
-7.62 brass is thicker than .308...less gun powder

The chamber pressure for .308 is/may be 12 000 psi greater than 7.62's max rated chamber pressure.

There is a great deal of information out there on the 7.62vs. .308. I had thought they were interchangable too.

[SavageCheesecake]

Theres also a 7.62 Nagant revolver cartridge.

[BPShunter]

Thanks for all the replies. I've always found it interesting when people talk about the difference between 7.62 vs. .308 ammo as well as 5.56 vs. .223 ammo. I have a buddy that works for Winchester ammunition and he tells me that the only difference between the civilian and military rounds was the stamping on the base of the cartridge. Maybe he is mistaken but I would think he should know if he works there. Oh well!

[45reloader]

Put NATO brass and 308 brass on a scale and see how much more brass is in a NATO shell case.

http://www3.sympatico.ca/shooters/7_62vs308.htm

This might explain further that the 2 rounds are not interchangeable without risk.

[Pappy John]

Clayfish and VUPDblue.....

I can see where the thinner brass and higher pressure of commercial .308 used in the larger NATO spec chamber could lead to case rupture, but I don't see the problem with tougher brass, lower pressure rounds in a commercial chamber speced out to higher pressures.

Could you elaborate on your reasoning?

All my reading on the subject, plus personal experience (plenty of Aussie and South African surplus sent downrange through my .308 Ruger Frontier), says otherwise, but I'm open to new ideas.

[VUPDblue]

I guess I really don't have a source... I always knew that it was bad mojo to use 5.56 in a .223 chamber so I assumed it was the same with .308/7.62. Pardon my ignorance on the subject. FWIW, I never use any of the above calibers in any of the other above calibers anyway.

[Clayfish]

The thicker brass leads to smaller case capacity and when fired in a tight chamber where the brass cannot expand the pressure spike is much greater than commercial .308. The biggest problem will come from a tight match chamber.