CincyLawman:
All I can tell you is that after about 500 rds. thru my USP40-C I noticed the same thing.
I accidentally discovered this one day and upon breaking it down noticed simply that the bushing would do just what you said. Aside from this being somewhat asthetically displeasing I can see no real harm done. I wondered myself why such a fine, and I do mean fine, weapon would have such an annoying characteristic.
Could be a problem if this noise ever gave you away in a situation. Mayhap we should give HK a ring up!
[This message has been edited by X-KILL (edited December 20, 1999).]