Greetings from the lovely Sierra Nevada mountains. I found this forum by searching for a 357 Sig barrel for an HK USP 40. I did not know that they were only made for the compact model. I very much enjoy my HK's. They shoot and shoot and shoot. A couple USP 40's, a USP 45, an HK 45, and an HK Tactical 45. In addition, I enjoy Benelli shotguns, and one of the Benelli's I purchased was imported by HK. So, I have an HK Benelli M1 Super 90. I like everything HK, and hope to purchase several more firearms as finances allow not that I am retired. I recently had an opportunity to purchase a USP 357 Sig Compact that was a very lightly shot police chief's sidearm. However, I waited until the next day, and somebody else bought it from a little local shop. I look forward to learning from the HK experts who post herein.