7.62x51 Lapua vs. .308 Lapua

TrevorF

TrevorF

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Hey Guys,

I acquired a box of old ammo recently and in it was a box of factory 7.62x51 Lapua ammo. Can I mix those now fired cases with my regular .308 Lapua brass or are there internal volume difference like with 5.56 vs. 223?
 
Weigh them dry, weight them full of water, see if there is a difference. That will answer your question.
 
I would not mix them.

I would not mix the same brand of ammo if it was different lot #s.

Then load data for your two flavours would be the same, but because of differences in things like neck tension, the groups could be different.

Mixing the brass adds another variable.

If your use is for plinking and hunting, not a big deal. if you are trying to make the best accurate ammo, keep them separate.
 
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Lapua brass, load and go esp in 308. thick necks, thick brass. What powder you are loading? Gun? Start low and work up. Lapua brass and a slow powder that fills the case I load and shoot. Same, same regardless of head stamp........
 
My lapua brass has 308 headstamps, but as pictured above, the box it came in has both on the labels.
 
If they weigh the same after prepping, I wouldn't worry about mixing them up. If they're not the same weight by more than 1-2 grains, I would keep them seperate.
 
peterdobson said:
We have imported Lapua since 1994 and have not seen 7.62X51. Regardless, take Genderites advice.
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This stuff is very old. I have a picture of the original packaging on my phone somewhere. It came in a box of mixed ammo with some packages of ammo dating back to the 50's. Lots of old Dominion stuff. Cardboard shotgun hulls etc.

I'll toss it in with my AR10 brass and keep it away from my bolt gun brass.
 
Hi:

From Lapua: "But for some military customers we do mark that as 7.62x51. But then it is for special (single) customer and not for commercial sales."

Ganderite has answered, but would appreciate seeing a photo and hopefully it has part number, this, for interest sake.

Best regards,

Peter
Hirsch Precision Inc.
 
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This match ammo loaded with a 185 gr bullet at 2220 fps.

Stamp on the flap is 23-52 EJERO 866 4140

I don't know how different this brass is than the current LAPUA 308 brass. It might be the same.

However, this LAPUA 7.62 brass that I have is about 40 years old.

I don't like to mix lot #s of brass because it adds another variable. Not only might the brass be made differently, but one batch may be once fired and another could have been loaded 10 times.

I keep the lots separate and when I get a few failures, I toss the entire lot.
 
May I chime in?

I am running that exact same box of Lapua .308. It weighs in on around 173.1 to 173.9 grains.

I also have ACTUAL 1x fired 7.62x51 from Industries Valcartier Inc. on Average they weigh in at 184 to 185 grains (Deprimed, resized & trimmed to proper length, after Purchase)

You can't mix this ammo. You also have to load them differently as the 7.62x51 has a smaller internal volume.

Im just showing you that in weight alone, you can clearly see there is a big difference between 308 commercial and military 7.62x51
 
peterdobson said:
Hi:

From Lapua: "But for some military customers we do mark that as 7.62x51. But then it is for special (single) customer and not for commercial sales."

Ganderite has answered, but would appreciate seeing a photo and hopefully it has part number, this, for interest sake.

Best regards,

Peter
Hirsch Precision Inc.
Click to expand...

So, does this mean recently manufactured Lapua brass head stamped 308 match (not Palma) and 7.62x51 is of the exact same specifications??
 
Lafrenierej said:
May I chime in?

I am running that exact same box of Lapua .308. It weighs in on around 173.1 to 173.9 grains.

I also have ACTUAL 1x fired 7.62x51 from Industries Valcartier Inc. on Average they weigh in at 184 to 185 grains (Deprimed, resized & trimmed to proper length, after Purchase)

You can't mix this ammo. You also have to load them differently as the 7.62x51 has a smaller internal volume.

Im just showing you that in weight alone, you can clearly see there is a big difference between 308 commercial and military 7.62x51
Click to expand...

7.62x51 and 308 are externally about the same, Fully interchangeable.

The differences are that 7.62 has a specification for head hardness (to resist the rim being pulled off in an automatic action). A 308 might have softer brass.

The other difference is case capacity. Usually 7.62 are made beefier and are therefore heavier and have less internal capacity. But not always. I have had some lots of NATO 7.62 brass that was significantly lighter than most 308 brass.

So avoid sweeping statements, just weigh your brass to see if it needs a bit less powder because of less capacity.

For example, if I switch from LAPUA to IVI, I would use about 2 grains less powder.

I weighed two samples of LAPUA brass. One is stamped 308 and one is stamped 7.62. The 308 case is slightly heavier.

308 171.12 gr

7.62 168.4 gr

The 7.62 ammo was loaded with a 185 gr bullet and intended for shooting at 1200 yards. I don't know if the weight reflects the need for case capacity or was just a variation of one lot to another.

Both these samples are older cases.
 
Lapua 7.62X51 and .308 Winchester are the same specification, but of course variations occur over time and lot to lot.
Obviously this is generally not the case.

We actually have some Lapua ammo used by a military unit in Europe and it is marked .308.

Best regards,

Peter
 
Well I finally got around to cleaning out my brass bag after shooting all that 7.62x51 lapua brass. Each one of them was cracked vertically along the bottom similar to incipient head separation. Must have been brass that had been loaded many times.
 
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