Military round comparisons

[stanc]

Of course, if a long barrel is needed to extract the performance you want without going to a bigger and more powerful cartridge, then there's an obvious answer...work on a decent* bullpup design, and enjoy a 20 inch barrel in a gun the same overall length as an AR-15 with a 10-12 inch barrel.

*fully ambidextrous without having to dismantle and rebuild the gun, and with an adjustable stock length.

Trouble is, such a "decent" bullpup is, at this point in time, no more than a theoretical possibility. Unless and until somebody makes it proven reality, it isn't worth discussing.

Which means we're limited to whatever performance can be extracted from the 14-16" barrel of a conventionally-configured carbine.