Is it 308 Winchester or 7.62x51?

**Gunowner99** · November 21st, 2017, 09:54 PM

Bolt action:

https://www.sportsmansoutdoorsuperst....cfm/ID/165268

So, what do you buy to feed it?

**Marcus99** · November 21st, 2017, 09:57 PM

I have a Savage model 12 in .308. Of course the manual states to only use the caliber stamped on the barrel(.308). I've never shot 7.62 out of it.

**Gunowner99** · November 21st, 2017, 10:01 PM

I assume my 30 cal cleaning brushes etc. are suitable as well?

**gghbi** · November 21st, 2017, 10:15 PM

Originally Posted by Gunowner99

Bolt action:

https://www.sportsmansoutdoorsuperst....cfm/ID/165268

So, what do you buy to feed it?

I suggest loaded cartridges! IIRC if it is marked 308 Winchester, you may fire 308 Win or 7.62 X 51 ammo in it safely, but if it is marked 7.62 X 51 you should only fire that ammo in it. Something to do with thinner wall 308 commercial ammo over expanding in the larger 7.62 x 51 military chamber. I am sure someone will be along to confirm or deny this. Any 30 caliber cleaning gear should be fine.

https://www.ammoland.com/2017/06/7-6...he-difference/

**USMC3531** · November 21st, 2017, 10:34 PM

short answer is it doesnt matter. if it was a gas op semi auto you can still shoot either as long as you stay around 150gr as heavy hunting ammo can beat up semi autos.

**spartakis252** · November 21st, 2017, 10:52 PM

Originally Posted by gghbi

I suggest loaded cartridges! IIRC if it is marked 308 Winchester, you may fire 308 Win or 7.62 X 51 ammo in it safely, but if it is marked 7.62 X 51 you should only fire that ammo in it. Something to do with thinner wall 308 commercial ammo over expanding in the larger 7.62 x 51 military chamber. I am sure someone will be along to confirm or deny this. Any 30 caliber cleaning gear should be fine.

https://www.ammoland.com/2017/06/7-6...he-difference/

You are sorta mostly correct, .308 Win. has higher chamber pressures than 7.62x51mm (due to the military round being used in machine guns). It's the exact opposite of the .223 vs 5.56 where the military round is higher pressure than the commercial designation.

In summary .308 Win can fire anything but if it is designated 7.62x51mm than stick the appropriate cartridge.

Edit to further answer your question, Bullet weight is determined by rifle twist, if it's 1:10 the heavier grains (168 and up) usually work best, 1:12 would be 168 and lighter.

**danhr** · November 21st, 2017, 10:53 PM

.308 has slightly higher pressures.

You can shoot 7.62x51 out of a .308 chamber.... But you not supposed to vice versa.

It doesn't matter if it's semi or not... That hardly makes any sense.

Something to start with is federal gold medal match ammo. Either 168 or 175 gr.

**Tacgunner** · November 21st, 2017, 11:08 PM

Just search for: Converted Spanish Mauser on the web. Plenty of pics showing why not to shoot .308 in some rifles made just for 7.62 NATO. Of course, if you reload, you can adjust your ammo to the gun and not worry about something blowing up.

**Delkal** · November 21st, 2017, 11:45 PM

I don't buy the pressure ratings. The different book numbers are probably from comparing the original CUP units and the Modern PSI readings. It makes it seem like the .308 is hotter but its not. The published ballistics for the .308 and 7.62 are for all practical purposes the same. If you have the same case, and the same velocity........that means you have the same pressure.

The cartridges are totally interchangeable. When was the last time you heard of a M-14 or an FAL blow up because someone shot a .308 out of them? Its a theoretical internet legend.

Now you do need a faster burning powder for some gas operated rifles like the M-14 or even a Garand in 30-06. But that has to do with the pressure curve to operate the op rod. The peak pressure can be the same.