The Gen X Arms and Ammunition® Xtreme Carbine is a custom build available in 25-45 Sharps and our proprietary 8x38mm and 375KO. The barrel is a 1 in 10" twist button rifled barrel. The upper and lower receiver are made from 7075 T-6 heat treated aluminum..The carbine is handsomely appointed with a VRS-T Keymod Free Floating forearm, Magpul MIAD grips, and a Magpul MOE buttstock. Additional calibers considered upon request.