FN HAMR-16

For those of you up to date on your firearms news you’ve undoubtedly heard of the recent announcement that FN Herstal is discontinuing (mostly) the SCAR series of rifles. If you haven’t heard then I hate to be the one to tell you, but the beloved short-stroke legends of SOCOM may well now be in their waning years. I wanted to take this as an opportunity to take a look back at some of the SCAR programs highlights, and in this case in particular, one of its known but oftentimes less understood rifles. The FN HAMR-16.

For many of us our first introduction to the FN SCAR was Call Of Duty, (Battlefield 2 if you were me) and I’d wager for those who grew up seeing the at the time new SCAR the first time you saw it was in its debut to the game franchise in Modern Warfare 2 as the FN MK.17 (SCAR-H) making it practically a staple of the franchise from then on, making an appearance in some form or another. If you were a fan of the lesser appreciated, and in my personal opinion criminally underrated CoD: Ghosts then you’re likely familiar with the FN HAMR.

The HAMR may hold the outward appearance of a SCAR, unsurprising given its a member of the family, but in function it’s anything but. FNs entry into the US IAR program, the FN Heat Adaptive Modular Rifle, or HAMR is a Light Automatic Rifle/Light Machine gun designed in 2008 and making its first major public appearance at AUSA2010, and going on to become one of the four finalists in the IAR program, eventually losing to the H&K M27 IAR. It is at its core similar to the FN SCAR the major difference setting it apart being its unique ability to adapt its firing mechanism to the chamber temperature of the weapon. In its default state it fires from the typical, and expected closed bolt, however as the rifle heats up due to firing it will automatically transition to firing from the open bolt without any input from the user, likewise returning to closed bolt when sufficiently cooled. This feature naturally, being to prevent ammunition cook offs during prolonged periods of suppressive fire. This being controlled by a phase change thermal actuator present beneath the enlarged heat shield under the barrel of the weapon connected to the chamber.

Other differences setting the HAMR apart from the rest of the SCAR family include its substantially heavier barrel, a noticeable increase in heat shielding at the front of the rifle, and the addition of more screws at the rear of the receiver presumably to reenforce the rear from the expected increase in volume of fire during its intended employment. The HAMR has been seen sporting a slightly different black lower receiver most often as of recently, but has also been seen with the standard FDE/Tan lower we come to expect from FN. Additionally the presence of a bayonet lug has been both present and absent depending on the specific rifle.

While the FN HAMR did not ultimately win the IAR contract with the United States, it has not been entirely cancelled as far as can be ascertained. It is still in development according to FN as of 2018, and has been seen, and is confirmed to still be in testing with FN as of 2019 albeit under the different name of the FN XLAR still exclusive to the 5.56x45mm NATO cartridge. While the FN HAMR has only officially been seen chambered in 5.56x45 NATO, there are unsubstantiated, and unofficial murmurs of a 7.62x51 NATO version having been made for testing in the past.

While I cannot argue the mechanisms effectiveness on thermal mitigation, and reduction, personally I would imagine that the sudden and likely unexpected change in firing, and recoil impulse from closed to open bolt would feel peculiar to say the least. Undoubtedly unexpected, unpredictable, and possibly unpleasant to the user as well. Despite this the HAMR is the only notable automatic rifle to feature such a mechanism making it hold a dear, and special place in my heart, as well as in the heart of firearms nerds, and technical enthusiasts.