The M4/M4A1 5.56mm Carbine is a lightweight, gas operated, air cooled, magazine fed, selective rate, shoulder fired weapon with a collapsible stock. It is now the standard issue firearm for most ...

The Ukrainians weren't used to the M4, so they had to overcome some psychological barriers and past habits. "But when a rifle shows results, it quickly changes your mind to it," he said.

It works with the M4 Carbine, the M249 machine gun, and the H&K and M16A2 rifles. It is suitable for use in most weapons with a 1-in-7 barrel twist. The M855A1 has a copper-jacketed steel core ...