Gun Thread

['73 H1 Triple]

Originally Posted by Rider

Yes but a 7.62 x 51 is not exactly the same as a .308 from some of the gun forums I've been on. I've heard that damage could be done to your rifle using the surplus 7.62.x 51 rounds in a .308 rifle. Is this in fact true or is it safe to use them?

Although the dimensions of the 7.62 x 51 NATO round are virtually identical to the .308 Winchester round, the 7.62 x 51 are loaded to a higher SAMMI spec ( chamber pressure )

What kind of firearm are you thinking of shooting the 7.62 x 51 round in? What kind of shape is it in?

[Rider]

Originally Posted by '73 H1 Triple

Although the dimensions of the 7.62 x 51 NATO round are virtually identical to the .308 Winchester round, the 7.62 x 51 are loaded to a higher SAMMI spec ( chamber pressure )

What kind of firearm are you thinking of shooting the 7.62 x 51 round in? What kind of shape is it in?

Fairly new Savage rifle model 11. Probably had 3-20rd boxes fired through it.

[fnfalman]

This is my personal experience, so take it for what it is.

I have yet to have successfully blasted 5.56/7.62NATO ammo (not reloads) through my .223/.308 rifles. Every time I tried, within a round or two possibly three at most, the brass would swell and stuck in the chamber. I literally had to kick the bolt handle back to extract. This happened with good quality surplus GI ammo or First World surplus ammo and not Russian/Chinese steel case ammo.

.223 and .308 on the other hand; even reloads (quality reloads from people who knew what they're doing), went through my military semiautos just fine.

[OTB]

Originally Posted by fnfalman

This is my personal experience, so take it for what it is.

I have yet to have successfully blasted 5.56/7.62NATO ammo (not reloads) through my .223/.308 rifles. Every time I tried, within a round or two possibly three at most, the brass would swell and stuck in the chamber. I literally had to kick the bolt handle back to extract. This happened with good quality surplus GI ammo or First World surplus ammo and not Russian/Chinese steel case ammo.

.223 and .308 on the other hand; even reloads (quality reloads from people who knew what they're doing), went through my military semiautos just fine.

And this is the headspace issue I was talking about. If you have an exceptionally tight chamber, as the rifle heats up you may have issues with chambering. I've had .308's that would shoot 7.62 with no issues. If you are experiencing issues with chambering, don't use the 7.62 ammo. On the other hand, .308's in 7.62 rifles, especially those that have been reloaded, have a history of head separations in SOME rifles,as the overly generous 7.62 go/nogo chamber dimensions caused excessive thinning of the already thin .308 brass at the base IN SOME RIFLES, causing separations and/or blowouts.

Due to manufacturing tolerances, every chamber is going to be slightly different; depending on how the chamber go/nogo tolerances between the .308 and the 7.62 overlap on your specific rifle. Your .308 rifle may not work with certain ammo. The 7.62 chamber tolerances were set generous for a reason; so that they could shoot a variety of ammo found at hand from different manufactures in different NATO countries. Sporter .308 dimensions are tighter, allowing for less tolerance to specific ammo, especially reloads. That's just the way it is.

If your .308 rifle won't digest 7.62 ammo, hot or cold... don't use it. If you are shooting .308's in a 7.62, watch for base thinning. You may even want to mic a couple of fired cases to see how much case stretch you are getting. Much beyond .007-8 and you are getting into case failure range.