RIFLING (TYPE & TWIST) – Polygonal, 6-sides, Twist rate, 1 turn in 25 cm (9.84 in)
BULLET DIAMETER – 9.02mm (0.355 in)
BULLET WEIGHT – 7.45 g (115 grains)
MUZZLE VELOCITY – 355 m/s (1,166 fps)
MUZZLE ENERGY – 471 j (347 ft/lb)
WEIGHT (EMPTY) – 0.865 kg (1 lb 15 oz)
WEIGHT (LOADED) – 1.157 kg (2 lb 9 oz) loaded with 18 rounds
SIGHTS – Open, iron, adjustable, Front sight – Square blade on dovetail base with single dot insert, Rear sight – Square notch on dovetail base with two-dot inserts, adjustable for elevation and windage
This, the first in a series of Expert HK pistols, was designed to me usable in international Practical Shooting Confederation (IPSC) matches. To qualify for the competitions, the weapon much fit in a container of specific dimensions, 225 x 151 x 45 mm (8.86 x 5.94 x 1.77 in). The Expert line of USP pistols all fit the IPSC dimensions very closely.