Hyde-Inland M2 Submachine Gun

The Hyde M2 is the missing link between the M1 Thompson and the M3 Submachine Gun.  With the demand for the Thompson quickly outstripping existing engineering capacity US Army Ordnance began to seek alternate designs.  

The experienced submachine gun designer George Hyde had submitted his Hyde 109, a refined version of the Hyde Model 35 for testing earlier in 1939. However, the weapon was rejected and the Thompson became the US Army’s standard issue submachine gun.  

Hyde Model 35 (Source)

In early 1942 when it became clear that a STEN-like weapon which could be quickly and easily produced on a war footing was needed. Hyde continued working on submachine gun designs at the Inland Division of General Motors and was ready to submit his new weapon, the Hyde-Inland-1.  US Army Ordnance tested the weapon in April 1942 finding it to be both accurate and extremely controllable in automatic fire due in part to its in-line stock, large bolt and slower cyclic rate of ~530 rounds per minute.  During a test of fully automatic fire at 50 yards the Hyde-Inland-1 put 99 out of 100 rounds fired onto the 6x6-inch target, 50% more hits than the Thompson M1.

Some minor changes were recommended by the testing board including converting the Hyde to fire from standard Thompson stick magazines then in production.  On the 30th April the Hyde-Inland was recommended for adoption by the US Army as the US Submachine Gun, Caliber .45 M2.  It was adopted as the substitute standard to the M1.  

The new M2 was used a blowback action and was lighter than the M1 weighing 4.19kg.  While the design was relatively straightforward it was not easy to manufacture.  It required skilled labour with the bolt’s diameter varying along its length.  As a result the M2 required considerable amounts of machining and raw materials to produce. The US Army had adopted the complete opposite of what it has been seeking; a simple, cheap and quickly built weapon. 

Marlin were contracted to manufacture 164,000 M2s at a cost of $36.76 per weapon. This was only marginally cheaper than the eventual production cost of the Thompson M1’s $44 per unit cost.  Production of the M2 should have begun in December 1942 however, delays with sub-contractors and problems with new powdered metal processes meant the first M2s were not delivered until May 1943.  

George Hyde’s simpler and more cost effective M3 (source)

In the meantime George Hyde, with the assistance of Frederick Sampson the chief engineer of the Inland Division of General Motors, had developed a new simpler design which could effectively be mass produced.  This weapon, the M3 ‘Grease Gun’, was rapidly readied for production in June 1943.   Marlin were only able to deliver a limited number of M2s for routine evaluation before issuing.  During these evaluations the M2 was found to suffer from a number of problems including weak recoil springs and some other component weaknesses.  With the cheaper and faster to manufacture M3 beginning production the US Ordnance Committee declared the M2 obsolete on the 14th June 1943.  

The M3 became the new substitute standard and would eventually replace the M1.  It is believed that only 400 M2s were actually manufactured and that none of these were issued or saw action.

Sources:

Images One & Two Source
Images Three & Four Source

The Complete Machine Gun, I. V. Hogg, (1979)
'The Hyde-Inland US M2 Submachine Gun’, F. Iannamico, (source)
Military Small Arms, I. Hogg & J. Weeks, (1985)