So school me on .308 vs 7.62x51 which barrel to buy

[rockyfatcat]

I am about to go the 80% lower route on an ar10. Which barrel gives me the most options? Like the 223 wylde I would like to be able to shoot both.

What do I need to know?

 

[Plinker66]

Maybe you should build a 6.5 Creedmoor then sell it to me cheep.
Kicks less carries better drifts less.

 

[palmettomoon]

If you shoot .308 in a 7.62x51mm chamber you'll blow yourself to kingdomcome. At least that's what I read on the internet after shooting 15,000 rounds of each type in the other marked chamber. Maybe you'll be lucky like me.

 

[Falcon1]

^^^^That

 

[Greybeard]

308 is just reversed as 223 in pressure. The nato round in 7.62x51 has less pressure than the 308 round, just as 223 has less pressure than 556. Hope that helps.

 

[ReservoirDawg10]

Plenty of very good articles online that explain the differences. The main difference is pressure. Get something chambered for 308 and you are good to go.

 

[Radar363]

Let's see if I can get cmshoot in here...
...sometimes he avoids threads like this...

 

[cmshoot]

Let's see if I can get cmshoot in here...
...sometimes he avoids threads like this...

Good info above.

 

[cmshoot]

Differences:

Headspace-
.308: 1.632”
7.62: 1.645”

Max pressure-
.308: 62,000psi
7.62: 58,000psi

Milsurp 7.62 brass is much thicker than commercial .308 brass. This translates to less case capacity.

 

[Plinker66]

I heard they lightened up 762 cuz those NATO fellers can’t handle 308 like Americans can.