Buy the barrel made by the manufacturer - Heckler & Koch Threaded Barrel, HK VP9, 9mm

There are many after-market barrels made for this pistol that cost much more than the HK version. But why would you buy one? This is made from the original cannon-grade or ordnance-grade steel that is a proprietary blend of metals that HK will never disclose it's composition of. It seems impossible that a 3rd party could do a better job than the original Mauserwerke could. This is a drop-in polygonal barrel that sits precisely into the HK slide along with the micro-ground feed ramps and the famous and renown Ulmer antler proof stamp adorned on the barrel. In keeping with German law, the serial number is stamped on the side, but not the exposed side. It will no longer match the numbers on the rest of the firearm. This barrel is approximately 3/4th of an inch longer than the standard length so expect that you will achieve about 18% greater velocity. It does NOT come with a thread protector; therefore you must find a 13.5 X 1 LH protector to add to it. HKParts sells a genuine HK version for $25. The thread protector also will fit the threads of a Glock, SIG and Walther and is therefore a European metric or DIN standard thread.