By Lars Dalseide | March 26 2013 12:33

Canada's take on America's tradition M16 design for Canadian Armed Forces

Canadian Colt light support rifle

The March edition of American Rifleman delves into Rough Rider machine guns, lever gun cartridges and the Annual Meetings in Houston. But what caught our eye this afternoon was Christopher R. Bartocci's piece on the rifles used by Canada's military:

M-16s of the Great White North: Diemaco & Colt Canada
Canadian troops have served side-by-side with Americans on the front-lines in the Global War on Terror since the beginning. And although their rifles look similar to U.S.-issue guns, the Canadian C7 and C8 families have features unique to the Canadian Forces.

Canadian involvement with the Colt M16 series of rifles began as a result of that country’s Small Arms Replacement Program (SARP), which sought to supplant the FN-FAL-based C1A1 rifles chambered in 7.62x51mm NATO that had been in use by Canadian troops from 1955 to 1983. The winner of the program for the new Canadian battle rifle was the Colt M16A2.

After adoption in 1983, the Canadian government assigned Diemaco contracts to manufacture the guns for Canadian Forces, and the Colt Technical Data Package (TDP) was licensed to the Canadian government to build the rifles. The Canadian government also entered into a licensing agreement with Colt that prohibited sales that would compete with Colt in the United States. Originally a division of Magna Int’l, in Kitchener, Ontario, Canada, Diemaco was established in 1976 with a mandate to become the center of excellence in small arms for the Canadian Forces, by providing engineering and development of future small arms and, eventually, to manufacture the new Canadian C7 service rifle.

Although the C7 was based on the M16A2, the Canadian military did not accept it as originally designed by Colt. Our neighbors to the north required some major changes to make the rifle suitable for Canadian Forces. First, the three-round-burst system had to go, as the Canadian military believed ammunition conservation and effectiveness of automatic fire were training issues, not mechanical ones. The second major change was that the Canadians would not accept the U.S. Marine Corps-mandated fully adjustable rear sight, believing the original “A1”-style rear sight was less complicated and far more practical as a combat sight. Another change was the addition of a buttstock spacer.

Canadian C7A2 5.56x45mm NATO rifle

Aside from those relatively minor modifications, which largely addressed the rifle’s functionality, the most significant change was to the barrel. It retained the M16A2 outside profile, but, inside, the chrome-lined bore, the rifling and chamber dimensions were not of standard Colt design. That was because Diemaco cold-hammer forged its barrels, a process used by Steyr, Heckler & Koch and Glock to name but a few. The barrel starts as a solid bar stock blank with a pilot hole drilled through the center. The blank is then placed in an Austrian GFM hammer forge. A mandrel is placed inside the pilot hole, and the machine exerts tons of pressure on the outside surface in a rapid multi-hammering process drawing the barrel blank out roughly one-and-a-half times its original length and cold-forging the blank around a mandrel, which forms the chamber, leade and rifling.

Along with the C7 family of rifles came the C8 family of carbines, which retained the early 14.5"-long lightweight profile, “pencil” barrel. The C8 was equipped with a two-position telescopic polymer stock. Another modification of the C7 utilized a flat-top upper receiver—one the Canadians referred to as having a “Weaver profile.” It predated the adoption of the MIL-STD-1913 rail of the M4 and is not compatible. The new rifle with the flat-top upper receiver was designated C7A1 and, correspondingly, the carbine was designated C8A1. Existing guns could be converted by replacing only the upper receiver while retaining the original barrel. That made a full-scale changeover quick and inexpensive.

Read the rest of Bartocci's piece on the M-16s of Canada's military on American Rifleman's Zmag.


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