[HankB]

I see Brownell's is now selling .50 BMG uppers for your AR15: http://www.brownells.com/.aspx/pid=4086 ... R_RECEIVER

I'd read a little about this type of conversion some years back, but with Brownell's now stocking it, the idea seems to have gone somewhat mainstream.

The AR15 lower is aluminum . . . I know that with the AR platform shooting normal rounds ( .223, 6.8 SPC, even .50 Beowulf) most of the stress is taken up in the upper; that's why plastic lowers work. But a bolt action .50 BMG will directly stress the lower.

Does anyone else think this is asking more of an aluminum lower than is prudent?

 

[Daniel Watters]

The real stress is taken by the steel barrel extension.

 

[Daniel Watters]

Of course, this could be the basis of an interesting experiment for one of our resident gunwriters. Skip directly over the aluminum lower and mate a .50 BMG upper to a polymer lower like the old Cavalry Arms model.