An AR15 type rifle chambered in 7.62×51 – I have a problem with finding the right ammo?
by admin on Sunday, November 20th, 2011 | 9 Comments
As we all know you should not put .308 Winchester rounds into a rifle chambered for 7.62x51mm.
Well, in my hunt for non surplus 7.62×51 I can only find one brand (Federal) and the specific item is out of stock and cannot be backordered on Cheaper Than Dirt.com.
Do you know of any reliable 7.62×51 ammunition brands that are not surplus, will feed smoothly in semi automatic rifles, and most importantly high quality?
I have been doing military competition with the 7.62mm NATO round – along with hunting and long distance competition with bolt rifles in 308 Win.
I am also a reloading instructor and ballistics technician.
In 35+ years of using milspec ammo in my hunting guns, and 308 Win in my 7.62mm chambered M1a rifles – I have nothing bad to say about putting one inside the other.
I have never, ever – heard anyone ever say you cannot substitue one for the other. And I have spent more time around 7.62mm ammo than most any other person alive. With one exception – when you pull the 147gr FMJ ball off of M60 linked ammo – it’s not very accuracte stuff – and should only be used out to 200 yards. This is because linked ammo is intenionally made slightly inaccurate – they want a ‘cone of fire’ coming from the machine gun, not pinpoint accuracy where several rounds go through the same hole. Machine guns need to ‘mix it up’ a bit to be more useful.
We do not have any 7.62mm vs. 308 issues like the 5.56mm vs 223 does due to technology changing in the twist rates and bullet weights that we’ve seen in 223 Remington.
I’m sure somone, somewhere, – probably a bench rest shooter – has a rifle that hates 7.62mm and does wonderful with 308 ammo or vice version. But that 1 person and his opinion does not a hill beans make for the rest of the millions of rifles. We see issues like the this come up when bench rest and bolt gun shooters visit and try to convince everyone to never crimp their ammo because it kills accuracy…………. but ar shooters need that crimp to prevent the bullet from back seating during chambering and blowing up the gun. One gun design’s accuracy is another gun design death.
The reason you have no ammo – is because you are following some sort of weird urban legend. Perhaps you should get off the internet and spend more time around people who actually get out and shoot this stuff.
In the first place there is no reason not to use surplus 7.62 except for a few types (Pakistani for instance). Almost all European production is first rate.
In the second place the differences between 7.62 and .308 are that the military specification chamber is slightly longer to accommodate ammo that is slightly dirty and that the listed *maximum* chamber pressure for the .308 is higher. That’s not necessarily the working pressure, just the max allowable.
You aren’t finding civilian 7.62X51 ammo because there is no market for it. Everybody knows that .308 works.
You CAN use 308 in a 7.62 gun but not the other way round.
A modern AR chambered for 7.62 NATO will not have any problems shooting .308 Win.
If you must shoot 7.52 x 51, Winchester makes it for the commercial market. Cabela’s sells it as does my local outdoor shop.
Why not use .308? There almost exactly the same. You can use .308 in a 7.62x51mm no problem. And the other way around in most cases.
.308 WIN and 7.62×51 are completely interchangeable in a rifle in good condition. I regularly shoot both through my R-25. Only problem I find is that some brands of reman .308 are a little light and occasionally fail to fully cycle the action unless it is spotless and freshly lubed.
I think you are getting it confused with the .223WIN and 5.56×45 issue where the military ammo is loaded to a much higher pressure than the specs for the .223WIN.
Headspace – 7.62×51 and .308WIN cartridges are externally dimensionally identical. The only problem you will run into is with reloading. You can get away (usually) with only neck sizing a .308/7.62 if it was fired in a bolt action (or lever, etc). if you fired either in a military chamber, you will need to full length resize the cases. (And if its a MIL cartridge, ream/swage the primer pocket regardless of what it was fired in – mil-spec crimps the primers in.) NATO brass is also thicker AT THE BASE/WEB (not the entire cartridge) to provide extra strength to help make sure cartridges extract under bad conditions.
People get really hung up sometimes on numbers that they don’t understand.
The bottom line is you can use 308 Winchester in a 7.62 NATO/7.62x51mm. That should solve your problem. It is the other way around as far as NATO pressure rounds in 223/308.
If you are using an AR-10 type rifle (AR-15 would be a smaller frame firing with a cartridge with similar OAL length to a 5.56 NATO), I would advise against ATI 308/7.62, it normally doesn’t cycle the action in my LR-308 which has no problems with the other 10 brands of 308/7.62 that I have run through it.
You should be able to pick up 308 Winchester anywhere rifle ammunition is sold.
Oh, I’m not so sure!
The determinant factor is, usually, the headspace – Correct. If I owned a military 7.62 x 51mm firearm the first thing I’d do is know exactly what my chamber’s headspace is at the shoulder.
You didn’t mention what brand, but every modern AR 7.62×51 rifle I have looked at is chambered to handle a .308, so I doubt it will be an issue. Just remember that some non-FMJ ammo may have trouble feeding. Check with the manufacturer or owners manual.
To be perfectly honest, the only time would be concerned about using an arbitrary .308 load is when shooting old surplus military rifles.
Surplus 7.62×51 is usually pretty good, so I’m not sure why one would look to find commercial stuff in any case.