308 Win. vs 7.62 x 51 Nato

[My Toy]

I read that you shouldn't fire 308 win ammo in a chamber marked 7.62x 51 because of the different pressures these two rounds are loaded to. I'm interested in loading some ammo to NATO specs. for 7.62x 51 using H335 and 150 gr FMC bullets.
Anybody know where you can find reloading data for 7.62x 51?

 

[DaemonAssassin]

Who makes the bullet you are using? That is where I would check first.

You can always check here under 308, but be forewarned you will have to put less powder into the case, due to the difference in the case wall thickness.

http://data.hodgdon.com/cartridge_load.asp

Humor me if you will, who made the rifle you are wanting to load for?

 

[airsporter]

Hodgdon has online data with several 150gr bullets using H335. Pressures shown appear to be within limits for the 7.62x51. As already mentioned, military cases are generally thicker with less internal case capacity. So, if using military cases, drop back a grain or two.

 

[Traveler]

Hodgdon has online data with several 150gr bullets using H335. Pressures shown appear to be within limits for the 7.62x51. As already mentioned, military cases are generally thicker with less internal case capacity. So, if using military cases, drop back a grain or two.

Are your sure you meant to say a full grain or two?

 

[My Toy]

Who makes the bullet you are using? That is where I would check first.

You can always check here under 308, but be forewarned you will have to put less powder into the case, due to the difference in the case wall thickness.

http://data.hodgdon.com/cartridge_load.asp

Humor me if you will, who made the rifle you are wanting to load for?

Armalite AR-10ABF; will be using Hornady 150 gr FMC, LC-84 unfired brass, Winchester Large Rifle Primer.

 

[jimbobborg]

I reloaded all of my 7.62 NATO brass with 150gr pulls and IMR4895. 8 lb tubs of 4895 were $189 at a local shop. When I was done with the 7.62, I started loading 30-06 with the leftover pulls and powder for my Model of 1917. I've been happy using CCI LR primers with both cartridges.

 

[DaemonAssassin]

Armalite AR-10ABF; will be using Hornady 150 gr FMC, LC-84 unfired brass, Winchester Large Rifle Primer.

Call Armalite and ask if your rifle can shoot 308 and 762. I know that the RRA LAR-8 is marked 762, but after talking to RRA they verified that it can shoot 308 and 762 with no issues.

 

[Pinecone]

Typically the difference between LC cases and most commercial cases is 0.3 - 0.4 grains of powder for the same velocity.

But some commercial cases (Lapua for one) are about the same capacity as mil cases.

But as with ANY load, start 10% low and work up, checking for pressure signs.

The safe pressure in YOUR firearm is different from any other firearm.

 

[Franklin]

Typically the difference between LC cases and most commercial cases is 0.3 - 0.4 grains of powder for the same velocity.

But some commercial cases (Lapua for one) are about the same capacity as mil cases.

But as with ANY load, start 10% low and work up, checking for pressure signs.

The safe pressure in YOUR firearm is different from any other firearm.

that is backwards with the 7.62 though isnt it? some of the loads i have looked at ar 6 grains cooler in the 7.62 vs 308

 

[Franklin]

I had to call sig on mine. they said .308 was fine and the lower is stamped 7.62.

 

[molonlabe]

here is a link to a previous discussion especially the gun zone. I subscribed to the thread for future reference.

http://www.mdshooters.com/showthread.php?t=89316

 

[Pinecone]

that is backwards with the 7.62 though isnt it? some of the loads i have looked at ar 6 grains cooler in the 7.62 vs 308

Which source?

6 grains of powder is HUGE difference.

Especially for a cartridge that it loaded with somewhere in the low 40 grain range. That is 15% change.

 

[Pinecone]

If you read the article cited in the thread link, it points out that it is NOT a pressure thing, but a headspace thing.

But not all commercial brass is thinner than military. Lapua brass has almost the same case capacity as Lake City mil brass.

 

[Franklin]

Which source?

6 grains of powder is HUGE difference.

Especially for a cartridge that it loaded with somewhere in the low 40 grain range. That is 15% change.

hornady and sierra manuals. i will double check my numbers but i am pritty sure it was as much as a 6 grain difference depending on powder.

 

[Pinecone]

For similar velocity, the difference between the higher capacity commercial cases and the mil cases normally 0.3 - 0.4 grains will do it. The from a lot of people having loaded and chronod loads over and Sniper's Hide.

The typical .308 accuracy load is Sierra 175 gr Match Kings with 43.5 grains of Varget. 43.1 for Lapua brass (which is the same case capacity as Lake City). Max for most people is in the 44.5 - 45 grain range.