U.S. Soldiers using a Thompson Submachine gun in WWII.

In a move that is seen as quite surprising by many, the U.S. Army seems to be searching for some ideas for a new submachine gun; we’re hoping this means an airsoft gun version will be here at some point in the future as well!

It’s not clear why the U.S. Army is looking to adopt a new submachine gun… The last time they took on a new machine gun, the Second World War was in full flow, and many other weapon types have had multiple variations brought out since then.

However, there are some who are saying that it is most likely being done to fit in with the eventual adoption of a new assault rifle and rifle ammunition calibre.

Submachine guns were developed during the First World War as an alternative to the then slow-firing and bulky bolt action rifles. The new weapon class was designed to be compact while still effective, fully automatic in its firing capabilities and be able to take pistol calibre ammunition. These new guns were perfect for clearing the narrow trenches of enemy troops.

America entered the Second World War with the M1928AI Thompson submachine gun, which was usable with the same .45 ACP rounds that were being used in the M1911A1 pistol. Towards the end of the conflict, the Thompson was supplemented by the M3 “Grease Gun”; a quick-to-build, no-nonsense small arm. The M3 was able to be built for a fraction of the price of other firearms while also using .45 ACP ammunition.

Diagram of function of M3 Grease Gun

Diagram of function of M3 Grease Gun, the last time the U.S. Army changed their submachine gun

Submachine guns were eventually phased out in many armies and replaced with shortened assault rifles, which could pack the heavier punch associated with assault rifle rounds while still being compact enough not to affect manoeuvrability.

What Features Will the New Variant Have?

The U.S. Army has posted a Request for Information from the defence industry, which essentially outlines a list of “wants” in order to get information back from suppliers and manufacturers about whether they are able to make such a firearm.

The RFI details that the U.S. Army are looking for a Sub Compact Weapon (SCW) that can fire 9 x 19 mm (otherwise known as 9mm Luger) ammunition. It must also be capable of fully automatic firing, have a Picatinny rail for mounting optics, lights and other accessories, and also mentions the capability to mount a suppressor.

But why is the Army going to back to the submachine gun after so many years? With the future of the military and firearms very much at the forefront of decision making, this is not one that will have been made lightly. The service has made it clear that they are looking to adopt a new calibre of ammunition for its Next Generation Squad Automatic Weapon and next-gen carbine, with this possibly being the 6.8-millimetre round.

The M4A1 is the currently used carbine and is equipped with 5.56-millimetre rounds which is small and light enough for rear area troops and vehicle crews. However, the potential 6.8-millimetre weapon will probably be heavier and bulkier, meaning it will be more difficult to store in a truck cab which could cause issues in tight situations. The new variant is also likely to have a larger recoil, and rear area troops get less range time than those who are frontline.

Having a 9-millimetre submachine gun that has less recoil, is easier to carry and would offer good self-defence for troops who are infrequently exposed to combat would be preferable for the U.S. Army. It would also undoubtedly use the XM1153 Special Purpose 9mm round that by unveiled by Winchester at the back end of 2017; the same ammunition as the M17 Modular Handgun System (based on the Sig Sauer P320, which already has a rather lovely air gun replica, which you can find here).

So, when will we expect to see this new submachine gun? That much we don’t know, but if we get a decent RIF from it then we’re happy to wait! What do you think of the idea of a new submachine gun? Let us know your thoughts in the comments or on our social media channels!