Springfield Armory M6 Scout: Based on the USAF M6 Aircrew Survival Weapon, issued to aircrew from the late 1950s until the early 1970s, the commercial model is nearly identical to the USAF version, though there are a couple of minor cosmetic differences - a removable trigger guard and a barrel length of 18.25" instead of the 14" barrel of the USAF version to be in compliance with Federal firearms laws. The also have an optional .22 LR rifle barrel in lieu of the .22 Hornet.
The civilian version of the M14 by Springfield Armory is an excellent rifle. It was the U.S. military response to the AK-47. They're expensive, but worth it. It's .308 - 7.62x51 NATO. It's a great all around rifle for hunting, shooting and personal defense.