The Walther Arms Inc. Colt M4 Ops semi-automatic, .22-caliber, rimfire rifle is a true replica of the version of the M16 machine gun used by special-forces personnel in the U.S. military as of 2015. The gun weighs 5.9 pounds without the magazine and is 31.1 to 34.4 inches long.
The lower and upper receivers are made of aluminum. The gun has an Ops-length barrel, a quad skeleton fore-end and a collapsible stock, which are all features on the original special-forces weapon. The length of the barrel is 16.2 inches, and barrel twist is 1 in 13.75 inches. It has six grooves in the barrel, and ammunition-loading operation is by blowback. The muzzle thread is 8 by .75 millimeters. The magazine capacity is 10, 20, or 30 rounds, which are available as accessories.
The gun has an adjustable telestock, a rear sight adjustable for elevation and wind, a removable tactical rear sight, and a front sight adjustable for elevation. It has a functioning dust cover, a machined tactical railing with rail covers and a steel flash suppressor. Accessories include a carry handle, a compensator and a Special Forces Crane Stock.
Walther is the only manufacturer licensed by Colt to make the .22 long rifle, and it is the sole Colt tactical replica rimfire in production, as of 2015.