And here's the next one, since I'm on a roll;
Name: Springfield Model 1956 “Vicario” Rifle
Designer: Springfield Armory
Type: Gas-operated semiautomatic rifle
Caliber: .243 Liberty[1]
Feed System: 10, 20, 30-round detachable box
Adopted: 1956
Notes: Although the M1944 did acquit itself adequately during the South American War, the U.S. Military almost immediately began looking for a new rifle to replace it; not only was Melvin's design less robust than desired, the contemporary state of the art made detachable magazines a must for small arms[2]. Weapons trials were conducted in 1953 with input from representatives of all services (including the Army's quasi-autonomous Air Corps), and ultimately the design selected was one that was light, handy, accurate to 500 yards, used detachable magazines, and was produced by Springfield Armory[3]; the M1956 Rifle.
Designed by Santo Domingan mechanical engineer Nelson Vicario, it utilized a long-stroke gas-piston which, when fired, turned a two-lug rotating bolt. Almost immediately, the M1956E1 was devised which introduced a dust cover over the exposed operating rod along the right-hand side of the gun, with the intent of keeping the guide track clear of debris, dirt or mud[4]. It also introduced a three-round burst capability to provide an additional boost in firepower (the original design was semi-auto only), although this was no replacement for dedicated machine pistols [5] or machine guns.
While a reliable and accurate rifle, it never saw significant action in American service. However, it was an important weapon for two reasons. Most notably, it was chambered in the new standardized rifle round for the League of American Republics, which would be adopted by all LAR members (barring Associate members or British Commonwealth states, who were already using a separate weapons/ammunition train). In addition, it was the primary weapon used by Colombian troops to repel Venezuelan aggressors in the American Theater of the Asia-Pacific War, easily outperforming the aged and ungainly PQ-45 selfloading rifle[6] most Venezuelans carried.
[1] OTL 5.56x45mm necked up to
this, with cannelured bullets to facilitate fragmentation.
[2] The Brits can take pride in leading the way here with their Taylor-Jalenson rifle.
[3] ITTL known mostly for manufacturing civilian sporting arms after the Civil War.
[4] Chalk it up to my unhealthy fascination with
InRangeTV and their rather brutal mud tests for this caveat.
[5] Can't remember if "submachine gun" was ever coined, or if the United States uses the German-derived "machine pistol".
[6] Picture the OTL Type 4 rifle, only chambered in a rimless variant of the 6.5x50mm Arisaka.