Keeping a few extra factory magazines around is never a bad idea; extra magazines save loading time at the range and also serve as a backup for those days when you simply cannot remember where you put your primary magazine.
HK Magazine HK USP for use with Jet Funnel 40 S&W 16-Round Polymer Smoke
Rainier LeadSafe Bullets 40 S&W, 10mm Auto (400 Diameter) 135...
$12.99 - $102.99
Bianchi T6500 Tac Holster LT Glock 20, 21, S&W M&P, HK USP 40,...
$82.99 & SHIPS FREE
MTM Dual Gauge Flip-Top Shotshell Box 12 or 20 Gauge 2-3/4"...
HK Barrel HK Thread Protector USP Tactical 40 S&W Steel Blue
Streamlight Stinger Dual Switch Flashlight LED HL (High...
HK Jet Funnel Kit USP 9mm Luger, 40 S&W Steel Blue