pros and cons of useing 7.62 x 51 in a 308
- Thread starter JakeRave
- Start date
I seem to remember something about the length or headspace specs being slightly longer in 7.62x51, so the majority or 762 will fit in a 308 bore, but there can be the ones on the far end of the tolerance that won't fit properly. I also recall the pressures are different, but i can't remember which is supposed to be higher.
If it were me i wouldn't shoot it in a target gun or my main hunting rifle, but for a plinker/practise trigger time at the range gun i wouldn't mind using it
If it were me i wouldn't shoot it in a target gun or my main hunting rifle, but for a plinker/practise trigger time at the range gun i wouldn't mind using it
(((Echo)))
CGN frequent flyer
- Location
- Old Man Land, AB
I fire factory 308 ammo in my Norc M305 all the time and it's rated as being 7.62NATO. I get more case stretching around the web so fewer reloads from the brass but it's perfectly safe with virgin brass. Everyone I know with an M305 shoots factory 308 ammo mostly and no one has ever had any issues.
7.62NATO ammo in a 308 chamber is even safer than the other way around. Just make sure you don't use the ammo with mild steel jackets instead of copper unless you want a smooth bore eventually. If you run into some cases with longer head space such as the article (((Echo))) posted then the bolt probably wont close in which case you can't fire them anyway.
Military ammo does have tougher primers than civilian ammo though. With a new Rem 700 it shouldn't be an issue but I have seen guys with older 308 hunting rifles that had FTF's with surplus 7.62NATO ammo.
7.62NATO ammo in a 308 chamber is even safer than the other way around. Just make sure you don't use the ammo with mild steel jackets instead of copper unless you want a smooth bore eventually. If you run into some cases with longer head space such as the article (((Echo))) posted then the bolt probably wont close in which case you can't fire them anyway.
Military ammo does have tougher primers than civilian ammo though. With a new Rem 700 it shouldn't be an issue but I have seen guys with older 308 hunting rifles that had FTF's with surplus 7.62NATO ammo.
Civilian .308 usually runs at a slightly higher pressure and higher velocity than 7.62NATO. Not significant and generally they are very close to the same. Exterior case dimensions are identical but the chambers are cut different with NATO chambers being looser to chamber more crudely made ammo and to function when really dirty.
Thin civilian brass in a really loose military chamber can cause cause ruptures (rare from the reading I've done but possible, especially with reloads). Thick military brass in tight civilian chambers can sometimes not chamber if the cases are poorly tolerances but are otherwise perfectly safe.
The differences between .223 Rem and 5.56NATO are more significant than the difference between .308 Win and 7.62NATO.
I think that you are thinking of 5.56 NATO and .223. I think he has it right.
This happened to a guy at the range once. He was throwing out the "duds" and I asked if I could have them. They all fired first strike out of my Norc M305. It was the Russian Baurnal stuff.
Just as an FYI:
223 - 55,000 psi
556 - 62,000 psi
308 - 62,000 psi
762 - 60,000 psi
223 - 55,000 psi
556 - 62,000 psi
308 - 62,000 psi
762 - 60,000 psi
A strongly built 223 bolt rifle can handle the extra pressure of 5.56 NATO but some civilian guns, semi autos especially, aren't designed for it. All manufacturers say to not use military ammo in any civilian gun for liability purposes.
"Civilian .308 usually runs at a slightly higher pressure and higher velocity than 7.62NATO."
Nah, that doesn't hold up in court.
Any variation in pressures between any factory 7.62 or .308 ammo is just that....the simple variation you will find between the production of any the same thing by different manufacturers, or even different lots by the same maker. Factory .308 and 7.62x51 are the same thing. Look at a few labels, some makers even put both designations on their boxes.
Your mother is also your father's wife, your aunt's sister, your gramma's daughter, etc.
Nah, that doesn't hold up in court.
Any variation in pressures between any factory 7.62 or .308 ammo is just that....the simple variation you will find between the production of any the same thing by different manufacturers, or even different lots by the same maker. Factory .308 and 7.62x51 are the same thing. Look at a few labels, some makers even put both designations on their boxes.Your mother is also your father's wife, your aunt's sister, your gramma's daughter, etc.
blasted_saber
CGN Ultra frequent flyer
- Location
- A blue part of Ontario
I have several boxes ammo which state
7.62 NATO (.308 WIN)
7.62 NATO (.308 WIN)
"Civilian .308 usually runs at a slightly higher pressure and higher velocity than 7.62NATO."
Nah, that doesn't hold up in court.
Your mother is also your father's wife, your aunt's sister, your gramma's daughter, etc.
You do realize that "7.62 NATO" and "7.62x51mm" are not the same thing, right? Simply listing the dimensions in mm's without the "NATO" name is just the European classification of the cartridge. ".30-30 Winchester" in European nomenclature is "7.62x51mmR" and has nothing to do with NATO (though a lot of Europeans still use the common name). It is true that when most North Americans say "7.62x51mm" they mean the NATO version but if a European box of ammo says ".308 Winchester/7.62x51mm" it does not mean it is the NATO cartridge unless it actually says "NATO". It only means that the product was designed to be sold both in the US and European markets. I have never heard of any US ammo manufacturer putting both designations on the same box because of the common use of 7.62x51mm to automatically mean the NATO version.
Officially there is a 2000 psi difference in the maximum pressure between .308 Winchester/7.62x51mm and 7.62 NATO even though they are interchangeable. It only accounts for a 3% increase in pressure and any proof cartridge is well above that.
I'm not saying they aren't interchangeable in any rifle designed for one or the other; read the rest of my posts and you will find I am saying the exact opposite.
Some civilian semi auto rifles can get prematurely worn out by shooting 5.56 NATO ammo and most manufacturers tell you to never shoot military ammo in their guns for liability reasons. This declaration from manufacturers has helped greatly to spread the fear that military ammo will make civilian firearms explode. A guy at the range once was shooting 5.56 NATO through a Kel-Tec SU-16 and it was spitting out fireballs with each shot vs. .223 which had practically no muzzle flash at all.
I have heard that the Austrian AUG jams a lot with .223 ammo because it isn't at a high enough pressure to operate the gas system properly. I have no experience with that myself though.
European or American? Perhaps in Europe they realize they are really the same thing even though many North Americans have an unfounded fear of mixing the two? If it's Chinese ammo I would assume it's just their short cutting things.
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