[ASA Vet]

M-16/AR-15 platform can be changed in seconds with an upper receiver swap

Changed to what?

[SJSAMPLE]

9mm
6.8mm SPC
7.26x39mm (AK round).
.40SW
.45ACP
.50AE
.50Beowulf

You name it, as long as a magazine will still fit in the lower.

[SJSAMPLE]

Oh, and you can even slap on a .50 BMG (yes) upper ;)

Try that with the Tavor.