SIG M5 Spear Deep Dive: Is This a Good US Army Rifle?
Semiauto Rifles
•
35m
The NGSW (Next Generation Squad Weapon) program began in 2017 to find a replacement for the M4, M249, and 5.56mm cartridge. It came to a conclusion in April 2022 with the formal acceptance of the SIG M5 rifle, M250 machine gun, Vortex M157 optic, and the 6.8x51mm cartridge. SIG released a handful of civilian semiauto M5 / Spear rifles and thanks to Illumin Arms I have one to examine.
The rifle (Spear is its commercial designation; M5 is the military one) is an evolution of the SIG MCX, which is in turn an evolution of the AR-15 and AR-18 systems. The MCX move the recoil spring assembly into the top of the upper receiver, allowing the use of a folding stock. It also has very easily swapped barrels and a suite of fully ambidextrous controls. Scaled up to AR-10 size and chambered for 6.8x51mm, the MCX became the Spear.
That new cartridge (commercial designated .277 SIG Fury) is designed to produce high muzzle velocities out of short barrel (the M5 has a 13 inch barrel).It does this by boosting the operating pressure up to an eye-watering 80,000psi, which required the development of hybrid case using a stainless steel case head. This allows the case to handle those pressures safely. The currently available commercial ammunition is loaded to lower pressure, however. Much of the military and civilian use of this rifle will be done with downloaded training ammunition, which uses a conventional all-brass case.
Both the M5 and M250 were ordered by the Army with suppressors on every weapon, a significant advancement in Army policy. The can is another SIG development, entirely made using additive manufacturing and designed specifically to prevent gas blowback into shooters' faces (which is succeeds at wonderfully).
Overall, I believe the M5 / Spear is an excellent rifle - soft shooting, reliable, and very accurate. However, that does not mean it is the right rifle for the Army. Will its ability to defeat modern body armor prove worth the tradeoff in extra soldier combat load weight and reduced ammunition capacity? Only time will tell...
Up Next in Semiauto Rifles
-
MDRX Micron: A Truly Tiny SBR Bullpup
The MDR has been out in the market for five years now, and DesertTech has been making some improvements. The current production model I called the MDRX, to denote several incremental improvements that have been made to the system. The gas block now has drainage holes, the polymer blend has been s...
-
Roller-Delay Showdown: Angstadt MDP-9...
Today we are out at the range to compare the Angstadt Arms MDP-9 to the classic H&K SP-5. We will do a bunch of runs on a course of fire that incudes precision targets, spinners and stars, and see which of the carbines comes out ahead! Plus, as a bonus, some shooting with a suppressor and subsoni...
-
But Does it Take 1911 Mags? Prototype...
One of the really cool aspects of the Cody Firearms Museum is that their collection is built largely on the original Winchester factory collection. Thus they have a significant number of prototype Winchester designs that were built and tested, but never put into production. One of them is this Wi...
