This project was conceived in 1983 with production models beginning in 1984. As with the other P7 models, the lead designer on this project was Helmut Weldle. This was a significant design change for the P7 series, because in 9mm and other caliber P7s, the barrel was not removable
Records indicate that there are 64 models in what are called Vorserie, or prototype series. They number in range from 8701-8764.
Production for non-U.S. consumption started with serial number 101, and for the U.S. started with 001.
Currently the most expensive variant of the P7 series, due to limited production numbers and numbers imported into the USA, it goes for $1500 and up for a P7 K3 in either caliber, with the .22LR Kit (Slide, Barrel and Magazine) going for $1500 and up also. The individual factory barrel kits in either 9mm kurz or 7.65mm currently go for $500 and up. A complete set of all calibers in the box recently sold for over $3500!
One issue with the P7 K3 is that the oil filled buffer that is designed to arrest the rearward slide movement when shooting the 7.65mm and 9mm kurz cartridges is highly prone to failure. At that point, it is likely that damage can occur to the pistol if you continue to use the pistol with the failed buffer. The .22LR kit does not use the buffer and can be safely shot on the gun with a failed buffer.
Recently (in 2010), there have been replacement buffers marketed on GunBroker that allegedly is a valid replacement approved by HK USA. While pricey, they are the only source of the replacements available to P7 K3 owners.
From the GunBroker Ad:
|Fairly Rare "KH" P7 K3|
||My P7K3 with TROS threaded Barrel and Suppressor|