Springfield M1A

[bobski]

so the bottom line answer is.....the .308 Winchester and 7.62x51 NATO are not the same.
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. 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.
so it stands, its not a wise practice to put 308's in a gun designated 7.62nato.

 

[cruzerlou]

I have a Springfeild M1A "Loaded" that I bought in 2008 .I must say that it was the best money I've ever spent on a gun .I love mine .I've added the Gen 4 Springfeild scope mount and a 4x16x40 ilumated red or green rectale A.O Mil-Dot scope to it .With Lake city surplus ammo it will hover at 1 M.O.A. 3 shot 100 yard groups .With my pet handloads using Serria Matchking 168gr B.T.H.P's over 40.9 gr's of IMR 4064 ,new Winchester brass and CCI 300 primers and an O.A.L. of .2800 ,the gun will shoot sub M.O.A.[around 3/4'] groups all day long .I'm going to add the National Match orp rod and gas block and glass bed the action and the only differnce between my "loaded" and the National Match will be the 1/2 M.O.A. rear sight that comes on the loaded gun as opposed to the 1/4 click M.O.A. sight that comes on the National Match gun that cost 500 bucks more than the loaded .I can upgrade mine like this for the cost of the parts and my time .The Orp.Rod and gas block cost 100 bucks each and a glass bedding kit is around 40 bucks .All thats left is my time installing the parts and doing the bedding.
This should shrink my groups up quite a bit .
As bobski said watch out shooting commershal .308 ammo in your M1A as the pressure can be too high and dammage your Orp.rod. there are Service load manuals that will give you safe loadind data for the M1A and M1 Grerand.
If you like I'll P.M. you load data for the M1A ,just P.M. me and let me know .
Your Friend,
lou

 

[David Bradshaw]

I like the standard 1" @ click M1 sights. The National Match 1/2 MOA is plenty fine. Going to 1/4 MOA clicks makes fast adjustment difficult and confusing----whether counting up or down. I prefer the rifle close to battle trim. The so-called coarse M1 sight remains the best battle sight I've used, and I cherish it's speed of adjustment, as well as its stability and repeatability.
David Bradshaw

 

[cruzerlou]

Yea I aggre Dave ,the 1/2 " M.O.A. sight is pleny fine enough foe me too .Besides my M1A always has the scope on it anyway .Every now and again I'll shoot it with the irons just to keep my skills up ,but most of the time I'm lookin to shoot those tiny litle groups with that big scope on it .
Lou

 

[David Bradshaw]

cruzerlou.... passing by this way again.... a friend has an M1A "Ultra Match," something like that. Stainless barrel, heavier than battle profile. I think a Springfield scope with crosshatch windage and elevation. Reticle too fine for practical, non-range, use. Certainly too fine for hunting.

I stood a 24" high x 12" wide, 1/4-inch plate at 300 yards. A left crosswind would blow the bullets off the plate. The rifle was zeroed at 100 yards. I took 8-shots.. Holding two hash marks below crosswire, one hash mark right, I ventilated the plate 7x8, offhand 300 yds. It is the shootability of an M1 Garand and the M1A which makes these rifles FUN.

Another issue may warp the military vs commercial ammo picture: military ammo is loaded for port pressure which does not batter operating rod, bolt, and action. Commercial ammo may not receive the same consideration.
David Bradshaw