M14 Forum banner

1 - 20 of 22 Posts

·
Registered
Joined
·
407 Posts
Discussion Starter #1
So I fire 7.62 American Eagle now I clean,size,trim the 7.62 brass. I load with sierra MK according to sierra .308 recipe. Now do I have a 7.62 or a .308 round
 

·
In the gilded halls of Valhala
Joined
·
13,515 Posts
I don't think 7.62 ae is a military case ?

Was the primer crimped ( not always a give away but it's something)

See how much water the case holds
If it's less than your commercial brass then it just might be 7.62

That's my laughable answer
 

·
Registered
Joined
·
5,442 Posts
All reloading dies are 308 winchester. All of us resize the case through a 308 die there for we have a 308 cartridge.
 

·
Registered
Joined
·
9,269 Posts
Will this never end?

THERE IS NO DIFFERENCE BETWEEN A 7.62x51mm CARTRIDGE AND A .308 WINCHESTER CARTRIDGE.

Let me know if you ever find a 7.62x51mm resizing die.

The differences are in the chambers of the rifles, not the cartridges. Please, PLEASE, tell all of your friends when you talk about this that there is no substantial differences between the cartridges.
 

·
Registered
Joined
·
9,269 Posts
Federal told me they are commercial cases
Yes, they are, because they are nothing more than .308 Winchester cartridges.
 

·
Registered
Joined
·
176 Posts
Wrong question to ask.

Only (useful) question to be asked: If what I now have - regardless of origin of case, primer, powder, bullet, regardless of headstamp, even regardless of what it says on the box/carton/can/whatever I put it in to take to the range, etc. - fits, chambers and functions properly in the rifle, puts the slug reliably downrange within the acceptable limits of accuracy, or at least gauges/is correctly loaded within the proper limits to do so, do I really care?

Call it/label it/describe it as either, or even BOTH - that's a "semantics" question, not a "function" question - as long as it safely and properly does what it should do in your rifle...why do you care?
 

·
Registered
Joined
·
1,872 Posts
It all depends if you use a metric or decimal micrometer.
 

·
Registered
Joined
·
407 Posts
Discussion Starter #10
Sorry to start a fury! Although my M1a is head spaced for .308 I almost exclusively shoot 7.62. I now have a browning Xbolt in .308 and just wanted to affirm that if I reloaded the 7.62 non military case I actually had a 308. Guess I should have realized from the start that they are the same !

Thank all
 

·
Registered
Joined
·
692 Posts
Sorry to start a fury! Although my M1a is head spaced for .308 I almost exclusively shoot 7.62. I now have a browning Xbolt in .308 and just wanted to affirm that if I reloaded the 7.62 non military case I actually had a 308. Guess I should have realized from the start that they are the same !

Thank all
Regardless of which rifle you are loading for, good practice is to bump the shoulder back just enough for that rifle, although this may mean slight adjustment each time. Usually ~0.004" for a SA and 0.001" for the bolt gun.
 

·
Registered
Joined
·
1,448 Posts
There is one idea that you should consider.

No military identifies their ammo as .308.
All designate it 7.62x51.

The reason is that .308 sporting ammo can be loaded from mild to WILD.
Where as 7.62x51 needs to be, at least, acceptable to all countries that use that caliber, like NATO.
So, there is some assurances that it won't damage or blow up their different weapons that use it.

Most all 7.62x51 is safe or marginally safe for military weapons chambered for it.
 

·
Registered
Joined
·
9,269 Posts
There is one idea that you should consider.

No military identifies their ammo as .308.
All designate it 7.62x51.

The reason is that .308 sporting ammo can be loaded from mild to WILD.
Where as 7.62x51 needs to be, at least, acceptable to all countries that use that caliber, like NATO.
So, there is some assurances that it won't damage or blow up their different weapons that use it.

Most all 7.62x51 is safe or marginally safe for military weapons chambered for it.
There is no guarantee what-so-ever that military 7.62 ammo is milder than civilian ammo. In fact, there have been tests that show that there is no real significant difference between the various .308 cartridge pressures and those of the military 7.62 cartridges. As I've posted many times, how could there be? First of all both cartridges use a max chamber pressure standard of about 60,000 - 62,000 psi and both have to stay within those pressure standards. Additionally, both cartridges have the same dimensions and use the same components so if you use the same powder and seating depth how can you possibly get a different pressure? What's more, one of our members has done some serious pressure testing over the years (using the same professional setup as SAAMI) and the highest pressures that he's ever recorded were with military 7.62 surplus ammo, not commercial .308 ammo.

Check out Larry Gibson's posts, if you'll note, he mentions that the highest pressures he's found were with specific lots of military M80 and M118SB cartridges, both were over NATO chamber pressure specs and far over commercial .308 pressures.

7.62x51... the real facts!

.308 in a 7.62 is a bad thing?

The reason that military weapons and ammo are marked as 7.62x51mm is so that users will know that they have been chambered and manufactured to NATO specs and that's important because there is a difference between the 7.62 and .308 chambers, a small difference, but enough to be of importance to the military. The cartridges are the same but the chamber is slightly larger in some dimensions for the 7.62 chamber. The only .308 cartridges that might seem over powered are the newer "Magnum" type loads and the problem with them is not that they achieve higher max average pressures but that their pressures stay high for a longer time period and this can be problem for rifles with gas ports. The rifle is designed to have a specific pressure that the port and the newer .308 magnum cartridges "might" have higher pressure at the port than what the rifle was designed for. I say might because it varies with rifle and cartridge design. Also, some .308 specialty cartridges used for precision shooting can be too long. If the bullet is seated too far out then it might jam in to the lands which can increase chamber pressures, but there isn't too much chance of that happening with most military rifles because the action will most likely jam before the cartridge could chamber.
 
  • Like
Reactions: IH 1026

·
Registered
Joined
·
407 Posts
Discussion Starter #14
Regardless of which rifle you are loading for, good practice is to bump the shoulder back just enough for that rifle, although this may mean slight adjustment each time. Usually ~0.004" for a SA and 0.001" for the bolt gun.
I'm using a lee collet die for the bolt gun, trying to use the FL die for bumping the shoulder ends up full length sized! Lol
 

·
Registered
Joined
·
692 Posts
I'm using a lee collet die for the bolt gun, trying to use the FL die for bumping the shoulder ends up full length sized! Lol
Bumping the shoulders is FL sizing. Matter of how much you screw die in to get the AMOUNT of shoulder bump.
 

·
Registered
Joined
·
1,857 Posts
So I fire 7.62 American Eagle now I clean,size,trim the 7.62 brass. I load with sierra MK according to sierra .308 recipe. Now do I have a 7.62 or a .308 round
When it comes to reloading a 55,000 psi cartridge... there is really no "laughable" question.

It is always better safe than sorry.

As others have said, it really boils down to how hot you load the .308 / 7.62x51 case. And the physical volume of the case itself.

Quote...


Before we go much further, we want to address the oft-posed question "Are the .308 Winchester and 7.62x51 NATO one and the same?" The simple answer is no. 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. "



I would suggest you use one specific brand case in your bolt action, that way if you do load it hotter than any of your M1A loads you can easily check.



Thanks for asking ! Again Better Safe than sorry.
 

·
Registered
Joined
·
1,448 Posts
Thats what I'm trying to say.

Military rifles under battle conditions can fire hundreds of rounds in a short period.

One consideration is the wear and tear on the gas system so military 7.62x51 is less power than the .308 sporting rifles that shoot far less rounds.

Also,as mentioned before, gas port pressure is an issue so that operating parts don't get damaged.
 

·
Registered
Joined
·
130 Posts
Yes, they are, because they are nothing more than .308 Winchester cartridges.
The internal volume is less on the 7.62 vs the .308 win, that is the only difference. if you put a .308 win max load in a military 7.62 case you could have a kaboom. be carful, like start 2-3 grains below book max then work up and watch for pressure (flat primers, primers coming out of pockets). This is because the military brass is thicker and if you make thicker brass and keep the original outside measurements then the internal volume must decrease.
 

·
Registered
Joined
·
9,269 Posts
If you want to get some real info rather than Internet rumors and false information try searching this site for the many other arguments about the .308 vs 7.62 issue or you can go to this link.

Or you can just listen to these guys rehash old wive's tales without checking out any of the factual data. By the way
while the 7.62x51 max is 50,000 psi.
, that's another one of those pieces of misinformation that most people don't bother to research, one of my links in my previous post explains why this is wrong, I wont waste my time to get in to it here.
 

·
Registered
Joined
·
9,269 Posts
The internal volume is less on the 7.62 vs the .308 win, that is the only difference. if you put a .308 win max load in a military 7.62 case you could have a kaboom. be carful, like start 2-3 grains below book max then work up and watch for pressure (flat primers, primers coming out of pockets). This is because the military brass is thicker and if you make thicker brass and keep the original outside measurements then the internal volume must decrease.
Kinda, sorta but not an absolute.
 
1 - 20 of 22 Posts
Top