In the 1970s, Gordon Ingram of MAC-10 fame developed his own .223 light rifle as well as a 7.62x39 and .308. Gordon Ingram scaled up the M1 Carbine into his SAM rifles. SAM-1 5.56, SAM-2 7.62x39, and SAM-3 7.62x51. It truly is a scaled up M1 carbine. Look how much the SAM-1 and SAM-2 look like my Mini-14 and Mini-30 below! I actually handled a SAM-1 at either a gunshow or the SHOT Show in the 1980s. I don't remember exactly. I bet the SAM-3 would be a beast to shoot, being that light of weight. Click on links for more info on Ingram's rifles.

Gordon Ingram SAM Rifles

Also, a better look at the SAM-1

More SAM-1

Kinda cool how much my Mini-14 and Mini-30 resemble the Ingram SAM-1 and SAM-2.