New Ultralight Arms Light Mountain Rifle in 243 Winchester. The Light Mountain Rifle is a named variant within the NULA line that emphasizes an even more stripped-down configuration — minimal stock features, slim barrel contour, and aggressive weight reduction targeting a finished weight below 5 pounds. In 243 Win the Light Mountain Rifle is one of the lightest accurate hunting rifles ever produced for the cartridge. Ideal for sheep and goat hunters counting every ounce. Type: Rifle Action: Bolt-Action Caliber: 243 Winchester Capacity: 1 Year introduced: 2005, USA Weight: 48 oz Overall length: 40" Status: Active Intended use: hunting, mountain hunting