in a 308 rifle can you fire 7.62x51?

[bob7122]

or is it like the 223 vs 556? for example i get the saiga 308 can i use military surplus on it with no prob?

[voiceoftheright]

Yes

[bob7122]

nice thanks

[KCDS]

same thing as .223/5.56 issue, but I think saiga actually can stand milsurp 7.62x51

[deadcoyote]

If I understand it correctly the .308 winchester is the round that is higher pressure than the 7.62x51. I've never heard of issues mixing these two.

[Nathan Krynn]

If I understand it correctly the .308 winchester is the round that is higher pressure than the 7.62x51. I've never heard of issues mixing these two.

You are correct that he .308 is higher pressure.

[kendog4570]

The 7.62 chamber is longer in its headspace dimension by .004".

The short answer is yes.

[eridepilot]

I have jamming issues with 7.62 in my .308 BLR. I believe it is due to the slightly longer case. The gun cycles better with the use of standard 308's and even better when reloading with a small base die set.

[MudCamper]

Can you? Yes. Should you? Absolutely NO.

If it's a Remington R-25 or a DPMS 308 chambered AR the answer from the manufacturer is a definite NO. See the following thread: http://www.calguns.net/calgunforum/s...d.php?t=248136

If you care about your gun or your safety, the answer is NO. See the following article: http://carnival.saysuncle.com/002453.html

People will tell you otherwise, but they are wrong.

[xrMike]

same thing as .223/5.56 issue

The rules are opposite between the 2 rounds:

• it's OK to shoot 7.62 (military version) in .308 (civilian version), but not the other way around

• it's OK to shoot .223 (civilian version) in 5.56 (military version), but not the other way around

[KCDS]

ah, silly me, thanks to pointing this out

[1994prerunner]

The rules are opposite between the 2 rounds:

• it's OK to shoot 7.62 (military version) in .308 (civilian version), but not the other way around

• it's OK to shoot .223 (civilian version) in 5.56 (military version), but not the other way around

your avatar looks like something off of 4chan.


...sorry man I just thought it was funny.

[fpeel]

The basic rule of thumb is that a .308 rifle can handle 7.62x51 ammo. But it's not about pressure, per se.

The SAMMI .308 specs are in Piezo-measured PSI. Military specs are derived from crusher-measured CUP (Copper Units of Pressure). The two scales can be loosely correlated using the formula 1.5 x CUP - 18,000 = PSI. (NOTE: there is NO direct correlation between the two systems! This formula is good for "rule of thumb" only.)

Using this formula the measured pressures in a 7.62x51 round in SAMMI PSI is 1.5 x 52,000 - 18,000 = 60,000. So the maximum chamber pressures for both rounds are not as far apart as they appear on paper.

Headspace should also be watched as putting a long 7.62x51 round in a tightly chambered .308 may result in bullet set back. That can raise chamber pressures significantly. Also, the slow burning powders used in some modern .308 rounds increase port pressures which can play havoc on auto loading military rifles.

As an example, my M14 and M1A are chambered for 7.62x51. They can also be fed certain commercial .308 WIN rounds because they are headspaced tightly enough AND because those rounds are made with a slow burning powder.

As an aside, with auto loaders there is also the consideration of using harder primers to avoid slam fires.

So, are the .308 and 7.62x51 interchangeable? Well, it depends.

(I realize a lot of this is a repeat of the discussion linked above. But I spent a lot of time typing it and didn't want to waste all these letters.)

[Sumo99]

My buddies NM M1a is chambered in .308 and the bolt won't fully close on 7.62 surplus ammo.

[rero360]

Well I have a tight necked, match grade Hart barrel on my .308, .342 to be exact. I shot some South African milsurp ammo thru it the other day with absolutely no problems. I'll let you draw your own opinion from that.