7.62 Question

[cdhc10]

What determines the use of the 7.62 round? Is the upper reciever or the lower reciever?

[Cohibra45]

What determines the use of the 7.62 round? Is the upper reciever or the lower reciever?

If you are talking AR-10 platform, you need both upper and lower dedicated to rounds of similar length. For the lower, the round length of the 7.62 NATO determines the magazine length and the magazine well size. For the upper, the bolt length and size along with the ejection port size is determined for that round also.

That said, the OAL of the magazine well and bolt length and ejection port opening will allow the use of various other cartridges including the new .338 Federal and down to 6.5 Creedmore among others.

Just like the 5.56 AR-15 platform allows the use of other rounds like the 6.8 SPC, 6.5G, .204 Ruger, .338 Spectre, 458 SOCOM, ect...

I hope this answers your original question.

[cdhc10]

so a 5.56 ar-15 lower will not accept the 7.62 round? Sorry if its a dumb question im new to these particular rounds.

[TOrrock]

so a 5.56 ar-15 lower will not accept the 7.62 round? Sorry if its a dumb question im new to these particular rounds.

Nope.

5.56x45mm vs 7.62x51mm

[Btrain]

so a 5.56 ar-15 lower will not accept the 7.62 round? Sorry if its a dumb question im new to these particular rounds.

It can take the 7.62 X 39 round