The rifle in question is a Browning semiauto.

Thanks!

Commercial .308 loadings are generally hotter than military 7.62x51 loads, so it is ussually safe to shoot surplus ammo out of a commercial rifle, but not necessarily the other way around.

With 5.56/.223 it's just the opposite.

Yes

There are no other differences between the Ishapore 2A and 2A1 rifles, but they are often incorrectly described as ".308 conversions". The 2A/2A1 rifles are not conversions of .303 calibre SMLE Mk III* rifles - they are newly manufactured, and are not technically chambered for commercial .308 Winchester ammunition. However, many 2A/2A1 owners shoot such ammunition in their rifles with no problems, although it must be stressed .308 Winchester may generate higher pressures than 7.62mm NATO, even though the rounds are otherwise interchangeable. The Ishapore 2A1 has the distinction of being the last non-sniper military bolt action rifle ever designed and issued to an armed force, and they are becoming increasingly popular with civilian shooters and collectors in the US, UK, and Australia as the supplies of affordable .303 British ammunition fluctuate.

From
en.wikipedia.org/wiki/Enfield_rifle

Just my 2cents, but, if you are chambered for .308 you should be good to go, if the rifle is in good condition.  If you have trouble with 7.62Nato you are in deep doo with .308 by my observation.

I bought Paki Mill surplus for my Ishapore and not WWB due to this.

People will post article after article on differing chamber dimensions.  Ammo is another subject.  The answer is yes, 7.62 is perfectly safe for .308 chambered guns.

It is, however, oftern MUCH easier to shoot .308 through a 7.62 than the other way around. The 7.62 neck dimensions are larger than the .308 Winchester. They are NOT identical....just very close.  As far as interchangeability,  it really depends on the chamber of the individual gun.  A Browning Auto might work just fine.  I have had SEVERAL issues with Failure to Extract from tightly chambered .308 bolt guns, however.

Run a few rounds through the gun and see how it reacts.  Personally, i would stick to .308 Commercial for the sake of the gun.

Thanks to all who replied!

Quoted: It is, however, often MUCH easier to shoot .308 through a 7.62 than the other way around. The 7.62 neck dimensions are larger than the .308 Winchester. They are NOT identical....just very close.  As far as interchangeability,  it really depends on the chamber of the individual gun.  A Browning Auto might work just fine.  I have had SEVERAL issues with Failure to Extract from tightly chambered .308 bolt guns, however. Run a few rounds through the gun and see how it reacts.  Personally, i would stick to .308 Commercial for the sake of the gun.

I recall this same discussion from another forum here.  I actually measured several different 308 and 7.62 rounds from different manufacturers and mil-spec from different countries and found they are all within tolerance to each other.  

As always with guns and ammo, somewhere there is a guy who had a problem with something. But for the rest of us, the ammunition is physically identical and pressures are nearly the same.  It should be noted that .308 Winchester was intended to be the civilian equivalent of 7.62mm NATO and was copied from preliminary specs from the US Army.

Here is a nice Q&A from Fulton Armory:

Clint, What's the difference between .308 Winchester & 7.62x51mm NATO? Jerry Kuhnhausen, in his classic Shop Manual (available from Fulton Armory; see the M1 Rifle Parts & Accessories or M14 Rifle Parts and Accessories Pages under Books) has published a somewhat controversial recommendation concerning .308 Winchester and 7.62x51mm NATO ammo, headspace & chambers. I broached the subject with him some months ago. He had his plate full, so we decided to chat on this in the future. When we do I'll report the results of our conversation. I completely agree with Jerry that if you have a chamber with headspace much in excess of 1.636 (say, 1.638, SAAMI field reject), you must use only U.S. or NATO Mil Spec Ammo (always marked 7.62mm & with a cross enclosed by a circle) since the NATO mil spec calls for a far more "robust" brass case than often found in commercial (read .308 Winchester) cartridges. It is precisely why Lake City brass is so highly sought. Lake City brass is Nato spec and reloadable (most NATO is not reloadable, rather it is Berdan primed). Indeed, cheaper commercial ammo can fail at the 1.638 headspace (e.g., UMC) in an M14/M1 Garand. Many military gas guns (e.g., M14 Rifles & M60 Machine guns) run wildly long headspace by commercial (SAAMI) standards (U.S. Military field reject limit for the M60 & M14 is 1.6455, nearly 16 thousandths beyond commercial (SAAMI) GO, & nearly 8 thousandths beyond commercial (SAAMI) field reject limit!). I also agree that 1.631-1.632 is a near perfect headspace for an M14/M1A or M1 Garand chambered in .308 Winchester. But I think that it also near perfect for 7.62mm NATO! I have measured many, many types/manufacturers of commercial and NATO ammo via cartridge "headspace" gauges as well as "in rifle" checks. If anything, I have found various Nato ammo to be in much tighter headspace/chamber compliance than commercial ammo. Indeed, sometimes commercial ammo can not be chambered "by hand" in an M14/M1A with, say, 1.631 headspace (bolt will not close completely by gentle hand manipulation on a stripped bolt, although it will close & function when chambered by the force of the rifle's loading inertia), though I have never seen this with NATO spec ammo. I.e., if anything, NATO ammo seems to hold at the minimum SAAMI cartridge headspace of 1.629-1.630, better than some commercial ammo! So, why set a very long 1.636 headspace in an M14/M1A or M1 Garand? It probably is the conflict mentioned above. Military headspace gauges say one thing, SAAMI headspace gauges say something else, as do the spec's/compliance covering ammo. In a court of law, who will prevail? I think Kuhnhausen gave all those who do this work a safe way out. However, I believe it not in your, or your rifle's, best interest. Whether you have a NATO chambered barrel (M14/M1 Garand G.I. ".308 Win."/7.62mm NATO barrels all have NATO chambers), or a .308 Winchester chamber, keep the headspace within SAAMI limits (1.630 GO, 1.634 NO GO, 1.638 FIELD REJECT). This subject is a bit confusing, and for me difficult to explain in a one way conversation! Clint McKee

With the noted exception of early rechambered Garands and the occasional oddly chambered gun with a long military chamber shooting thin commerical brass .308 ammo, this should not be a problem.