Originally Posted by
Hunter Rose
HK45's is a more standard recoil system with a delrin buffer (same as the USP 45 Compacts, just upscaled). The USP 45's recoil reduction system is a dual spring setup specifically designed to reduce recoil forces imparted on the pistol and increase longevity. The Mark 23 with this system was tested with 30K +P rounds plus 6K higher pressure proof rounds. Nothing broke. You've also got the Federal Cartridge USP 45 used for testing that went 297K+ rounds. Also, an LEO on HK-Pro had a duty gun with more than 100K rds documented on it. Additionally, HK rates the USP 45 for 45 Super in stock form, not so for the HK45.
The durability difference is really just academic when Todd's HK45 went 50K rds without issue, and there may not be a difference at all. However, the USP 45's system works, and if you tested 10 examples of each to destruction, I'd put my money on the USP 45 being the last pistol standing.