The Down Range Forum

Member Section => Tactical Rifle & Carbine => Topic started by: bobodean on September 13, 2009, 04:28:55 PM

Title: 7.62x51 NATO ammo ok in DPMS .308?
Post by: bobodean on September 13, 2009, 04:28:55 PM
Greetings all..
I have a DPMS 308L with 24" stainless barrel. Recently I had this gun at the range and all was fine. I was firing some Remington 180gr core-lock. Fired 20 rounds with no problems. Then I switched to some NATO stuff from 2005. After a few shots, the gun failed to extract. Upon finally getting the charging handle pulled back(very tough to do) the extractor had pulled a piece of the rim off. A cleaning rod was used to gently tap the brass from the chamber. It just took a touch and it popped free. The dealer where I bought this rifle told me that I should never,EVER use NATO ammo in this gun because it is in .308 and not 7.62x51 NATO. I thought they were the same. Previously, I had fired the NATO stuff with no problems. Whats the opinion?
Title: Re: 7.62x51 NATO ammo ok in DPMS .308?
Post by: Rastus on September 13, 2009, 05:03:54 PM
The two rounds are not the same.  You should only shoot what the manufacturer specifies.

Haz or Tom, can ya'll help out here?  I know one of you are on top of the difference and interchangeability issues.
Title: Re: 7.62x51 NATO ammo ok in DPMS .308?
Post by: Rob10ring on September 13, 2009, 05:32:41 PM
This is similar to the .223 not being the same as 5.56 NATO. I called both Colt and Ruger to make sure that I could fire either in my guns and found that I could. I would recommend doing the same. It will only take you a couple of minutes.
Title: Re: 7.62x51 NATO ammo ok in DPMS .308?
Post by: fightingquaker13 on September 13, 2009, 05:51:33 PM
I can't belive DPMS wouldn't chamber for surplus ammo. I mean, hello its an @#@#$ rifle! why would they not give max versatility. I would call them. If its not geared for the NATO stuff I will be dissapointed, but will learn from your misfortune. That really is too bad if its the case.
FQ13
Title: Re: 7.62x51 NATO ammo ok in DPMS .308?
Post by: CJS3 on September 13, 2009, 06:01:40 PM
7.62x51 NATO is not as powerfull as commercial 308 Winchester. As long as your weapon is chambered for 308, the NATO surplus is OK.

The reverse is true of 5.56 NATO compared to 223. You should never fire 5.56 surplus from a weapon marked for 223. Always check with the manufacturer if you're not sure.
Title: Re: 7.62x51 NATO ammo ok in DPMS .308?
Post by: billt on September 13, 2009, 06:40:41 PM
If it pulled a piece of the rim off it could be the ammo has the wrong pressure curve for your rifle. Most gas operated semi auto rifles like yours, the Springfield M-1A, and the M-1 Garand do not shoot well with ammunition that has powder with a slow burn rate. What happens is the pressure curve of the ammunition peaks too late, and can cause damage by cycling the gas system with too much pressure. This can cause all sorts of problems ranging from what you've experienced, all the way to bent operating rods and broken extractors. The new Hornady manual has seperate loads listed for the Springfield M-1A and the Garand because of this. These loads employ a powder with a mid range burn rate like IMR 4064, IMR 3031, or Varget. These powders allow chamber pressure to drop off before the gas port is exposed, thereby allowing the gas system to cycle without any undo force.

Springfield Armory has a list of suitable ammo they recommend for use in their M-1A rifles, and I'm sure DPMS has much the same. I would give them a call, or else shoot them an E-Mail. I'm sure they'll be glad to help.  Bill T.
Title: Re: 7.62x51 NATO ammo ok in DPMS .308?
Post by: tombogan03884 on September 13, 2009, 07:04:57 PM
7.62 X 51 and .308 Winchester calibers ARE interchangeable, When a company says (like DSA in their FAL's ) not all ammo is acceptable their list goes by maker or lot and it will depend on how hot the ammo is loaded. For example they may say do not use South African, Chinese or West German.
The chances of getting GOOD gun advice from a gun dealer is about the same as getting good CAR advice from a used car salesman.
Check your extractor, and check the rim thickness of the NATO  ammo compared to the factory load.
Title: Re: 7.62x51 NATO ammo ok in DPMS .308?
Post by: Pathfinder on September 13, 2009, 07:46:27 PM
Who made the milsurp ammo?

Generally, the .308/7.62 discussion is a non-starter unless the manufacturer has specific issues with one brand or another. It is not the same with .223/5.56 discussion, however, there should be no difference in shooting the .308 or 7.62. That is why I asked who made the milsurp ammo? If it is some crappo ammo, like the Pakistani manufacture, the variances in those cartridges cause a lot of a headaches, and is why generally people stay away (in droves) from the crappo stuff.

Anyone know of anything other than the Paki 7.62 that had cartridge quality issues?
Title: Re: 7.62x51 NATO ammo ok in DPMS .308?
Post by: tombogan03884 on September 13, 2009, 07:58:01 PM
This is the Ammo warning for DSA FAL's

http://www.dsarms.com/ammowarn.asp

Here's the link for DPMS

http://www.dpmsinc.com/
Title: Re: 7.62x51 NATO ammo ok in DPMS .308?
Post by: Fatman on September 13, 2009, 08:13:08 PM
Here's a quick copy of something I previously posted on what I found out about .308/ NATO rounds interchangeability, with a link to some good stuff:

Quote
Now, the important part. From what I've read, the NATO chambers can be longer and that meets milspec. The heavier case prevents problems here. If you check your NATO chamber with a .308 field gauge, and it swallows it, that NATO rifle cannot safely shoot the thinner commercial .308 and you must check it with a NATO no-go gauge and field gauge to see if it is still ok for NATO ammo. If it fails the field gauge, it's a wall-hanger.

Essentially, all in spec .308 chambers can shoot NATO, all in spec NATO may be able to shoot .308

http://armedcanadian.blogspot.com/2007/11/shooting-308-out-of-762-nato-chambers.html
 (http://armedcanadian.blogspot.com/2007/11/shooting-308-out-of-762-nato-chambers.html)



Title: Re: 7.62x51 NATO ammo ok in DPMS .308?
Post by: Bidah on September 13, 2009, 08:51:50 PM
I would expect that it has a match chamber as well.

-Bidah
Title: Re: 7.62x51 NATO ammo ok in DPMS .308?
Post by: billt on September 14, 2009, 08:52:15 AM
The thing that usually forgets to get mentioned in the .223 / 5.56 MM comparison, is the fact the difference between the two is in the chamber dimensions, not the cartridge itself. The 5.56 MM chamber has more freebore than the standard .223 chamber does. Yes, the 5.56 case is slightly thicker, but that can be said for most all military cases. All the freebore accomplishes is it allows the round to be loaded slightly hotter for more velocity, without increasing pressure to dangerous levels. Weatherby has done the same thing for years in all of their Weatherby Magnum calibers.

This all means very little today simply because most all ammo today has been downloaded because of this interchangeability. So it is "protection" for a non existent condition. For example Weatherby calibers are now being chambered in non Weatherby makes like Remington. They don't freebore their rifles like Weatherby does, so to safely compensate for this they download the ammunition so it is safe to fire in any chamber. This also holds true for the .223 / 5.56 MM. While the 5.56 MM might be a little hotter, it isn't enough to create any danger. A lot of this is due to the "advancement" of the legal profession. In other words we have too many lawyers in this country. Compare a loading manual from the 50's or 60's to a manual copyrighted today and you will see what I mean. All of the "maximum loads" are much less in todays manuals. Bottom line, you won't get into any trouble shooting 5.56 in a .223, or 7.62 NATO in a .308. I've been doing it for years, and have never seen any issues of high pressure in either caliber in literally dozens of rifles.  Bill T.
Title: Re: 7.62x51 NATO ammo ok in DPMS .308?
Post by: bobodean on September 14, 2009, 02:50:22 PM
So I should be ok then? I still have a large quantity of this NATO ammo, and I'd rather not give it away.
Could the problem possibly have been a combination of dirty chamber, insufficient lubrication, and new gun(less than 200 rounds fired)?
Title: Re: 7.62x51 NATO ammo ok in DPMS .308?
Post by: tombogan03884 on September 14, 2009, 02:56:41 PM
 I would hold off on shooting that particular lot of Surplus until you have talked to DPMS.
Title: Re: 7.62x51 NATO ammo ok in DPMS .308?
Post by: billt on September 14, 2009, 03:02:55 PM
I would give them, (DPMS), a call. If they say you are good to go, then give the gun a good cleaning, especially in the chamber area, and see if any problems persist. Take along some ammo you know works. That way you can isolate the problem. If it is the ammo, you'll know for sure.   Bill T.
Title: Re: 7.62x51 NATO ammo ok in DPMS .308?
Post by: MikeBjerum on September 14, 2009, 03:43:01 PM
Before I bought my 7.62 I talked to DPMS on the phone.  I can't remember everything he said, but he assured me that I could use both .308 and 7.62 with no problem.  When I got the gun the barrel is stamped 7.62.

Warning - this part is from my feeble old memory

I belive he told me all of their .308's will take the 7.62 unlike the .223/5.56 issues.

However, regardless of what the website, catalog, gun dealer, us on here or the barrel stamp say, I would call DPMS.  They are great people, and I have always found that it is like talking to an old friend when I visit with them.
Title: Re: 7.62x51 NATO ammo ok in DPMS .308?
Post by: Robert Black on October 22, 2016, 06:19:42 PM
I just bought a new DPMS  Oracle the barrel is stamped 7.62x51 the receiver is stamped .308 Win. I am REALLY confused after reading the other posts so I believe I'll call DPMS and see what the manufacturer says and post their answer
Title: Re: 7.62x51 NATO ammo ok in DPMS .308?
Post by: billt on October 25, 2016, 08:29:49 AM
I just bought a new DPMS  Oracle the barrel is stamped 7.62x51 the receiver is stamped .308 Win. I am REALLY confused after reading the other posts so I believe I'll call DPMS and see what the manufacturer says and post their answer.

It's very simple. Go by what's on the barrel. If the barrel is stamped 7.62 X 51, then that is all you should use. If the barrel is stamped .308, you can use both. It's the opposite of the .223 / 5.56 MM. In .30 cal. the higher pressure cartridge is English, (.308). In .22 cal. it's the opposite. The metric designation, (5.56 MM), is loaded to higher pressures than the English designation, (.223). Which is why 5.56 MM chambers are freebored.