DPMS LR308 chambered for 7.62 NATO or 308?

[seadevil]

I am preparing to buy a DPMS LR308 rifle.
They offer many of their LR308s chambered for the 7.62x51 NATO round, and they advise it is no problem to use 308 ammo in their rifle.

My question is do you think I should buy the rifle that is chambered for 7.62 NATO and can shoot 308 ammo too?
- or -
should I buy their rifle chambered only for the 308 round and cannot shoot 7.62 NATO? (DPMS does advise not to use 7.62 in their 308s)

Other than the obvious versatility of a 7.62 chambered rifle, being able to safely shoot both calibers, what are some other pros & cons?

 

[tju1973]

The only issues I have heard (here?) that some cheaper 7.62 surplus may get stuck in the rifle....not sure from personal experience. The BIL has an AR10, and his eat just about anything...Portuguese,SA, Indian, Commerical US, Russian...little to know trouble...

 

[W.E.G.]

Its up to the owner of the gun to figure out whether "its OK" or not.

I've never heard of .308 causing any sort of catastrophic failure in 7.62 rifles. While it may be true that .308 has a higher SAAMI-spec rating than 7.62 NATO, that certainly does not mean all commecial .308 is loaded to maximum SAAMI spec.


I measured various milsurp 7.62 ammo. One batch of Malaysian linked machine-gun ammo significantly exceeded the conventional .308 spec of 1.630" from the base of the cartridge to the datum-line on the shoulder. The only .308 I had on hand at the time of my measurements was a box of Federal Gold Medal .308. The Gold Medal measured within about 0.002" of the measurements I was getting for several of the various milsurp 7.62. I wrote a "report" of sorts on these measurements. You can read my report at http://www.falfiles.com/forums/showthread.php?postid=2160133#post2160133

One might speculate that third-world machine-gun ammo tends to be of greater "headspace" dimension (longer from base to shoulder datum-line) as the guns used by those countries are more worn-out than brand-new American guns. So much for a "standard" NATO spec.

Here's a quick summary of the "report."

 

[TexasPatriot.308]

just stick to the .308, problem solved. it aint worth the hassle.

 

[Z-Michigan]

It appears you know that they offer two different chambers, depending on the particular model.

I have read many places that while they are different cartridges with nominally different dimensions, "all" 7.62x51mm ammo is made with dimensions that fit inside of a .308 Win chamber. The wonderful data provided by W.E.G. indicates that two types of machinegun ammo from third world countries were outside of .308 Win dimensions, and all the 7.62x51 from more common and quality sources was within .308 Win dimensions.

Personally, unless using third-world machinegun surplus ammo is important to you, I would get whatever model you like best, without worrying about which chamber dimensions that model has.

 

[W L Johnson]

Well, as far as AR-10s are concerned, this is what Armalite has to say about their AR-10s

ArmaLite’s® larger AR-10 series rifles are all chambered with 7.62 NATO
chambers. .308 Winchester (SAAMI standard) ammunition functions perfectly in the
7.62 NATO chambers.