Firearm : Alexander Arms Tactical 14.5 carbine, with 14.5" barrel length Ammunition : 123gr Sierra MatchKing Prototype Calibration : all depths are corrected depths The prototype 123gr SMK impacted at 2385 ft/sec and penetrated 2" before yawing and fragmenting. (The 123 SMK is not currently a Sierra catalog offering.) The block was placed at a distance of 50 yards from the muzzle. Maximum penetration of the 123 SMK was 16.2", maximum permanent cavity diameter was more than 6" with lesions running to block exterior surfaces. Depth to the maximum permanent cavity was 7". Bullet fragmented into multiple small fragments with jacket pieces visible at 11” and 13”. Small core fragment was visible at maximum depth of 16.2". Brass Fetcher ballistic gelatin testing would like to thank John at http://www.65grendel.com for providing the permission to feature these test results and photographs on the website. We would also like to thank Alexander Arms http://www.alexanderarms.com and Speer http://www.speer-bullets.com for conducting the tests.