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eridepilot
08-03-2009, 1:16 PM
I just got a Browning BLR .308 and I have heard that I can use a 7.62 instead of a 308. Is this recommended and will it cause any harm on the rifle?

Thanks

ke6guj
08-03-2009, 1:18 PM
IIRC, you can use 7.62x51 ammo in a .308, but not the other way around.

Darklyte27
08-03-2009, 1:19 PM
Yes

http://www.6mmbr.com/308Win.html

.308 Win vs. 7.62x51--The Straight Scoop
Before we go much further, we want to address the oft-posed question "Are the .308 Winchester and 7.62x51 NATO one and the same?" The simple answer is no. There are differences in chamber specs and maximum pressures. The SAMMI/CIP maximum pressure for the .308 Win cartridge is 62,000 psi, while the 7.62x51 max is 50,000 psi. Also, the headspace is slightly different. The .308 Win "Go Gauge" is 1.630" vs. 1.635" for the 7.62x51. The .308's "No-Go" dimension is 1.634" vs. 1.6405" for a 7.62x51 "No Go" gauge. That said, it is normally fine to shoot quality 7.62x51 NATO ammo in a gun chambered for the .308 Winchester (though not all NATO ammo is identical). Clint McKee of Fulton Armory notes: "[N]obody makes 7.62mm (NATO) ammo that isn't to the .308 'headspace' dimension spec. So 7.62mm ammo fits nicely into .308 chambers, as a rule." You CAN encounter problems going the other way, however. A commercial .308 Win round can exceed the max rated pressure for the 7.62x51. So, you should avoid putting full-power .308 Win rounds into military surplus rifles that have been designed for 50,000 psi max. For more information on this interesting topic, read the following articles: Gun Zone's 30 Caliber FAQ; Cruffler.com Technical Trivia, June 2001; and last, but not least, Steve Redgwell's .308 vs 7.62x51 Analysis, which really provides a definitive explanation. Reloaders should also note that military ammo often is made with a thicker web. Consequently the case capacity of 7.62x51 brass is usually less than that of commercial .308 brass. You may need to reduce recommended .308 Winchester loads by as much as 2 full grains, if you reload with military 7.62x51 brass, such as Lake City or IMI.

eridepilot
08-03-2009, 1:28 PM
Thanks for the information. Will jamming or misfires be common using a 7.62 vs the .308?

reidnez
08-03-2009, 1:39 PM
Thanks for the information. Will jamming or misfires be common using a 7.62 vs the .308?

Shouldn't be an issue at all, they are dimensionally identical. The only concern is using .308, which has a higher pressure spec, in a weapon only designed for 7.62.

gunn
08-03-2009, 1:42 PM
Shouldn't be an issue at all, they are dimensionally identical. The only concern is using .308, which has a higher pressure spec, in a weapon only designed for 7.62.

Example: the Ishapore Enfields that were going for $150-180 from AIM surplus had a nasty habit of going kaboom when their owners would try shooting commercial 308 ammo in the guns that were (barely) re-designed to shoop 308 NATO ammo.

-g

fallbrook79
08-03-2009, 3:10 PM
on dpms rifles you can use both 308 and 762x51 in a barrel marked 762x51.if your barrel is marked 308 you can only use 308.from what i read 762x51 is .02 longer than the 308 and can cause wear to the throat of the rifling over time causing failure to extract.there is alot of talk about this on dpms forums since they make both barrels.im not sure if this matters for your rifle but its what ive learned lately since i bought my 762x51 upper from dpms

m1match
08-03-2009, 3:25 PM
Trying to relate 7.62mm chamber pressures to SAAMI .308 chamber pressures doesn't work because SAAMI and the Ordnance Dept. measured them in different ways that can't be compared. Here's more from Fulton Armory's website:

http://www.fulton-armory.com/308.htm

popeye4
08-03-2009, 3:46 PM
Bottom line for your Browning BLR: good to go. Dimensions are identical.

DanHuuN
08-03-2009, 4:20 PM
That just answered a question I had as well...Thanks!

Sailormilan2
08-03-2009, 5:12 PM
Trying to relate 7.62mm chamber pressures to SAAMI .308 chamber pressures doesn't work because SAAMI and the Ordnance Dept. measured them in different ways that can't be compared. Here's more from Fulton Armory's website:

http://www.fulton-armory.com/308.htm

One issue of the AMERICAN RIFLE last year had a short article on the 7.62 NATO vs 308 Win controversy. This article stated that some 7.62 NATO ammo had higher chamber pressures than commercial 308 Win ammo.
Springfield Armory marks the barrels on their M1As ".308Win" rather than 7.62 NATO, and state that commercial 308 can be used in their rifles.

Edited:
The AMERICAN RIFLEMAN, February, 2008, p. 20

"Unlike using 5.56x45 mm NATO ammuniton in a .223 Rem.-chambered guns, which the Sportings Arms and Ammunitions Manufacturor's Institute lists in its "Unsafe Arms And Ammunition Combinations," there is no such blanket prohibition in using .308 Win factory ammuntion in 7.62x51 mm rifles, or vice versa, but caution is required. The external cartridge dimensions of the .308 Win. and the 7.62x51 mm NATO are nearly identical, although the 7.62x51 mm barrels have a 0.013" longer chamber specifications, so there could be case head sperations issues with the thinner commercial .308 Win. cases. Also, military 7.62x51 mm loads can be encountered that exceed SAAMI's .308 Win. maximum pressure of 62,000 p.s.i. Of course, it's always best to use ammunition for which the barrel was designed."

vf111
08-03-2009, 5:21 PM
Also keep in mind not all 7.62NATO ammo is equal. I had some Argentinean 7.62NATO (not stamped w/ the NATO headstamp) that wouldn't chamber in a Browning Varmint rifle. It was a combination of "slightly on the bigger end of the tolerance scale" ammo and a tight match grade chamber. The Argie ammo however worked fine in an M1A and a DSA FAL clone.

UBFRAGD
08-03-2009, 6:30 PM
I thought 7.62 was loaded to higher pressures than 308Win.

Here's my story: I bought an M1A and a bunch of battle packs of 7.62. Within three hundred rounds my rifle was toast. The manufacturer replaced the barrel, bolt, etc....... When it came back, I finally pulled my head out of my butt and noticed the barrel was stamped 308Win. Since then I have only used 308Win and have not had one single malf in over 2000 rounds......

c good
08-03-2009, 6:58 PM
A good friend of mine has a .308 BLR. I let him try some of my 7.62 X 51 to see if it would work. It was too much trouble, not feeding, extracting etc. I wouldn't do it personally. c good

eighteenninetytwo
08-03-2009, 8:16 PM
Sorry but that nothing but urban myth. I have been collecting and shotting enfields for years and that myth and this discussion has been around for years. There is not one documented instance that I know of, or any of the other enfield types I know know of, of a 2A or 2A1 in decent condition doing the kaboom thing with .308.

QUOTE=gunn;2865343]Example: the Ishapore Enfields that were going for $150-180 from AIM surplus had a nasty habit of going kaboom when their owners would try shooting commercial 308 ammo in the guns that were (barely) re-designed to shoop 308 NATO ammo.

-g[/QUOTE]

Gunaria
08-03-2009, 9:12 PM
Simple answer yes you can. But it will not be accurate. Most 7.62x51 is 147gr. or less. Those Browning's where made to shoot 150 gr. and higher. How do I know this, I've done it with a Browning A-bolt. Shooting mil-surplus out of it made my paper targets look like I was shooting buck shot at it. Holes are all over the place. If you don't believe me go try it yourself.

Bigballaizm
08-03-2009, 9:13 PM
IIRC, you can use 7.62x51 ammo in a .308, but not the other way around.

Thats NOT the same for 5.56x45 & .223 right??
You can use .223 ammo in a 5.56, but not the other way around???

bernieb90
08-03-2009, 11:15 PM
I have tried Malasian ball 7.62 in my dad's BLR, and found that the feeding, and extraction was very difficult. The BLR does not give you the mechanical advantage of a bolt action or the sheer brute force of a gas operated rifle system. The same ammo works great in my M1A. It seems that the chrome lined chambers of the military speced guns really help with feeding slightly corroded ammo.

ck867
08-03-2009, 11:49 PM
Thats NOT the same for 5.56x45 & .223 right??
You can use .223 ammo in a 5.56, but not the other way around???

correct

fallbrook79
08-04-2009, 12:55 AM
in my opinion we pay too much money for these rifles to shoot different ammo than is stamped on the barrel.like i said earlier the more i read the more i get different answers contact the manufacturer.in my opinion

Bigballaizm
08-04-2009, 5:14 AM
correct

Thanx for verifying CK! I wasnt 100% sure...