Ever since my pals at Olympic Arms out in Washington State came up with a handgun built on the AR receiver, I’ve marveled at the number of other arms makers who followed suit.

Now comes Rock River Arms’ (1042 Cleveland Road, Dept. GDTM, Colona, IL 61241/(309) 792-5780/www.rockriverarms.com) PDS pistol, and it is a real piece of work. The “PDS” designation refers to this pistol’s patent-pending Piston Driven System that utilizes a “purpose-designed” bolt carrier, an adjustable gas piston and an over-the-barrel spring and guide rod setup. This eliminates the traditional AR-platform recoil system, while preventing gas blow-by to the rear of the receiver.

Chambered for the 5.56mm NATO and .223 Rem.., this beefy handgun features a full-length rail on top for mounting electronic or optical sights and an ambidextrous charging handle. The chrome-lined barrel measures 8 inches and is cut with a 1:9-inch rifling twist. It has a PDS-MD muzzle device with a ½-28 thread, and the gun features a Hogue pistol grip. Overall length is 17.5 inches.

New from CZ-USA (P.O. Box 171073, Dept. GDTM, Kansas City, KS 66117/(800) 955-4486/www.cz-usa.com) is the SP-01 Shadow Custom, a two-tone semi-auto with fixed sights, chambered in 9mm. It’s got an integral accessory rail on the dust cover, and slim-line aluminum grips.

Also new is the CZ Czechmate, another self-loader that is definitely for precision IPSC target work. Chambered in 9mm, this pistol has a C-more 6 moa red dot sight, two spare barrels, a compensator, spare magazines with capacities up to 20 and 26 rounds, and much more. It has a black polycoat finish and comes in a hard case.