DS Arms, Inc. of Barrington, Illinois, imports the Swiss-built TP-9 from the manufacturer, Brugger & Thomet. In 2004, it introduced the MP9, which it describes as a compact, lightweight submachine gun that is perfect for personal protection and self-defense. The gun's design follows Steyr's TMP with a few minor improvements to the frame and sights, although the gun is essentially the same.

The semiautomatic TP-9 has an interesting recoil operated, rotating barrel, locked breech action that is machined on state-of-the-art CNC equipment from 4140 steel. Upon firing, recoil drives the bolt and the barrel to the rear as one unit--which is locked together via lugs on the bolt that engage eight splines on the barrel--while a locking pin at the top of the barrel guide rides in a control cam cut in the barrel.

If the bolt becomes difficult to retract with the charging handle at the rear of the gun, a 9mm round can be inserted in the round hole in the side of the bolt.

This cam, or groove, follows a precise curve, and once the bolt and barrel have moved to the rear about a quarter inch, the barrel begins to rotate clockwise about 15 degrees. This action unlocks the bolt and allows it to travel the rest of the way to the rear, where it extracts the spent brass and carries it to the extraction point. Then it cocks the hammer, reverses course, strips a fresh round from the magazine and feeds it into the chamber.

The TP-9 is equipped with an ambidextrous polymer charging handle, which is located at the rear of the polymer top cover. The top cover also supports the adjustable rear notch sight and a front post, and a Picatinny rail runs the length of the top cover for mounting scopes or other optics.

The black polymer frame, also available in tan or olive drab, has a rail beneath the barrel for mounting a light or laser. At the rear of the frame is a bracket for the full-auto MP9's buttstock. Adding a buttstock to the semiauto TP-9 would make the gun subject to registration with the BATFE, so don't add one. (Don't put a vertical foregrip on this gun for the same reason.) However, the rear of the frame also features a handy attachment point for a sling. More about that later.

SPECIFICATIONS BRUGGER & THOMET TP-9
MANUFACTURER:	DS Arms, 847-277-7258
TYPE:	Locked breech, rotating bolt, recoil operated semiauto.
CALIBERS:	9mm
MAGAZINE CAPACITY:	15 or 30 +1 (10 round mags available)
BARREL LENGTH:	5 3/8 inches
OVERALL LENGTH:	12 inches
WEIGHT:	2 3/4 ounces
SIGHTS:	windage adjustable rear notch, post front
STOCK:	polymer
FINISH:	blue
EXTRA FEATURES:	top and bottom Picatinny rail; sling
PRICE:	$1,250

The TP-9 comes in a hard plastic, foam lined carrying case with a sling and, where legal, 15- and 30-round magazines, both made of see-through smoked polymer to allow for a round count. Ten-round magazines are available for states that limit capacity. The operator's manual suggests downloading magazines by one round to assure reliable functioning.

This unusual looking semiauto is 11⁄2 inches wide 65⁄8 inches high and is 12 inches long with its Width of this unusual looking semiauto with its 53⁄8-inch barrel. The gun weighs 23⁄4 pounds unloaded, although it looks like it should weigh more.

The TP-9 is equipped with a lever-type trigger safety, a firing pin drop safety and a manual safety located at the top of the grip that is activated by pushing it to the right. The trigger on the sample had a great deal of take-up and broke at 9.6 pounds with no overtravel. The bolt is held to the rear after the last round is fired by the bolt catch, which is located on the left side at the seam of the top cover and the frame at the centerline of the grip.