The best current ammunition choice for the M1 Carbine is the Remington 110 gr JSP (R30CAR)—at an average velocity of 1864 f/s, it expands to .54” to .58” and penetrates 13” to 16” whether in bare gelatin, through automobile windshields, or Level IIIa body armor. This is as good as many .223’s. <snip> The Winchester 110 gr JSP works reasonably well, but has a bit smaller permanent wound channel compared to the Remington load. Generally the Federal 110 gr JSP carbine bullet acts just like ball without any expansion. Hornady 90 gr JHP-XTP bullets offered insufficient penetration when fired from the carbine. Preliminary results indicate the new Barnes all copper 100 gr X-bullets for the .30 carbine to be a good choice, although we have not finished testing.