AR-.17. A preban Bushmaster lower, bushmaster ambi target set trigger, Pachmayr grip, JP reduced weight hammer, oversized pins, Ti firing pin, overweight fluted NM Peace River Arms chrome bolt carrier, chrome bolt, DPMS heave handguard, Colt M4 upper, ARMS #5 scope mount, 4.5X14 AO Leupold Vari-X III, JP adjustable gas block, JP Recoil Eliminator, and a 20 inch Heavy Barrel chambered in .17 Remington. With the lead buttstock it weighs 12 pounds empty. And yes the .17 Rem feeds in stock magazines and even the Betamag.
Thanks to Jason "F" Hinkle