The M14 was conceptually designed during the latter part of WWII when the Garand was being evaluated due to perceived shortcomings. The M1 Garand is a fine and functional battle rifle, one of the finest. The U.S. military wanted a lighter weapon with a detachable, higher capacity magazine (20), the ability to launch grenades, utilize a bipod, and have full-auto capability.
John Garand helped design the improved prototype designated the T20. Near the end of WWII a large order was placed for the prototype rifle but the war ended before the order went into production.
A shortened version of the 30.06 cartridge was being tested and designated the T65, later after the U.S. convinced NATO to adopt the new cartridge as the standard issue cartridge of the allied forces the cartridge came to be known as the 7.62x51 NATO.
Now that NATO had a standardized cartridge there was a move to standardize the battle rifle. Belgium, Britain, and Canada adopted the FN-FAL prior to the U.S. making a decision. During 1955 and 1956 the FN-FAL (T48) and the M14 (now designated the T44) were tested extensively. The U.S. found both rifles were suitable to use by the U.S. forces but chose to adopt the M14 instead. In 1957 the U.S. adopted the U.S. Rifle, 7.62mm, M14.
After the M14 was phased out of mainstream service it could not be sold to the public as surplus due to the perceived (by the DCM) ability of converting the weapon to full-auto. Large quantities of many unissued or brand new M14 rifles were destroyed. Many rifles were sold to U.S. allies including: Colombia, Estonia, Israel, Latvia, Lithuania, Philippines, and Taiwan to name a few of the larger recipients.
The M14 is still today carried in the U.S. military by snipers and special forces troops. This is a testament to the simplicity in function and overall superior design of the weapon.
In 1962 the Springfield Armory was directed to develop a Match rifle based upon the M14. This rifle included several modifications, including the elimination of the auto selector assembly and an improved barrel and sights. The design was shelved, but in 1974 the now privately owned firm of Springfield Armory began making semi-auto versions of the M14, called the M1A, built upon an investment grade cast receiver with U.S. issued M14 parts. The semi-auto version has no provision to be converted to full-auto capability. Many companies have produced either rifles, receivers, or parts for commercial version of the rifles.
The following is a list of some of companies that offer M1A rifles or parts:
Armscorp USA Fulton Armory Smith Enterprise, Inc. Entreprise Arms Springfield Armory, Inc.