What other calibers use the AR-15 magazine as-is ...

AR/M4 Beyond 5.56/.223
1

… and hence the magwell.

Just curious.

2

Pretty darn sure 6.8SPC fits 28 rounds to a 30 round 5.56 magazine.

3

same follower as well?

I read that 6.5MPC fits right in as-is

4

.50 Beowulf will work in an non modified ar mag.

5

You are incorrect.
The 6.8 SPC mag is different on the inside since the rounds are fatter.

:cool:

6

+1. It is different and as well as the follower

7

.223 and .222 both fit in the 5.56 AR magazine… :wink:

8

6x45.

9

7.62x40???

10

.458 socom