What Are M4 Feed Ramps?

M4 Rifle

• The M4 rifle was developed by Colt firearms in the early 1990s. The rifle is basically a shortened version of the M16 rifle with a shorter barrel and a collapsible stock. The M4 rifle is a select fire weapon capable of full automatic firing; it is not available to the civilian market.

M4 Feed Ramp

• Since the M4 rifle is designed for full automatic firing, Colt redesigned the feed ramps to guide the bullets into the camber at a high rate of speed (the automatic rate of fire from an M4 is approximately 700 to 950 rounds per minute). The M4 feed ramps were widened at the bottom to give the bullet a larger surface to catch on.

AR-15 Feed Ramp

• Feed ramps are nothing new̵1;AR-15 rifles have always had them. However, traditional feed ramps are rounded at the outer edge of the barrel extension, giving the bullet a smaller surface to guide it.

The M4 Feed Ramp Advantage

• Among civilian shooters the advantage of M4 feed ramps is a matter of debate. Since AR-15 rifles are semi-automatic (the trigger must be pulled for every shot fired), the standard feed ramps generally are very reliable in guiding the bullets during the loading process. But for shooters who want a little insurance against jamming, M4 feed ramps are a viable option.

Making Your Own M4 Feed Ramps

• It is possible to modify the feed ramps on your AR-15 rifle to be compatible with M4 feed ramps. By using a dremel tool you can widen the bottom feed ramps. You should not attempt to do this modification unless you are extremely competent with a dremel tool.