The 240 Origin Story: FN-D

The FN M240, or internationally the FN MAG, is probably the most successful and wide spread general purpose machine gun of the western world. It has also been called a medium machine gun or MMG in addition to the GPMG title which is associated with its multi-role and multi-variant nature.

How many variants? Well FN produced four. The Brits have twelve of their own. The Swedes have five. The US military has eight and that’s before the Barrett/Geissele. And then the Chinese made one illegally without license because, “F*ck you, we’re China.”

But Keith, Ian is showing a BAR that looks kinda like the Colt Monitor Variant.”

Correct. The Browning BAR (via Colt to FN) was the direct predecessor of the FN MAG. The BAR internals and operation were (and are) suited for sustained automatic fire. They just needed longer duration and that has always been best accomplished with felt feds. Pulling the internals out of a BAR look shockingly familiar to modern machine gunners.

As Ian covers, the FN-D introduces the barrel change mechanism that carried over to the FN MAG/240. That feature has, while perhaps less practically applied, sustained on variants to this day. The “barrel swap” in order to increase sustained fire rates and preserve barrel longevity is fantastic in theory but in consistently applied outside of training ranges (and sometimes even there) since taking your working machine gun apart in a gunfight you’ve clearly been at for a minute has its downsides.

Anyhow, take it away Ian. The FN-D.

Keith Finch
Keith is the former Editor-in-Chief of GAT Marketing Agency, Inc. He got told there was a mountain of other things that needed doing, so he does those now and writes here when he can. A USMC Infantry Veteran and Small Arms and Artillery Technician, Keith covers the evolving training and technology from across the shooting industry. Teaching since 2009, he covers local concealed carry courses, intermediate and advanced rifle courses, handgun, red dot handgun, bullpups, AKs, and home defense courses for civilians, military client requests, and law enforcement client requests.