1994 Reduced the slide weight by 1.1 oz.
Reason: improve reliability with training rounds and make gun easier to carry.
1994-95 Change to a polygonal barrel
Reason: Glock
1994-95 Change trigger transfer bar
Reason: Improve reliability in cold weather and dirty environments
1994-95 Change recoil guide rod to a "captured spring version"
Reason: Glock
1995 Change trigger mechanism.
Reason: Improve drop protection, reduce manufacturing costs, eliminate hammer over travel
1995-96 Add rubber spur to hammer
Reason: Required to pass some institution's drop test.
?? on date-change size of magazine release to current smaller button.
Reason: to prevent inadvertent mag releases?
1995-96 Change angle on slide lock
Reason: customers don't want slide to close automatically when a mag is inserted
2000 Add locking feature to hammer strut support:
Reason: attempt to pacify safety Nazis
2001 Converted captive recoil spring retainer from c-clip to
Machined end on Compacts.
Reason? C-clip prone to breakage on the Compacts.
2004 HK made the USP slide without the “HK” logo. Only “USP” on the left side and the text “Heckler & Koch” on the right side.
2005? Match hammer has a "D" cut in it. The match trigger kit now requires a new hammer catch and if not used will strike the firing pin when decocked.
Reason: ???
The catch part number is 219442. The new catch requires a new V1 hammer, part number 218571 (218570 complete). Looking at the pair (new catch and new hammer) in situ, the notch looks exactly like your match hammer notch and the catch fits nicely in the notch. Holding a LEM catch up to the new hammer (again, in situ) I believe the LEM kit includes the same new catch. I'll know for sure in a day or so when I get time to install the LEM kit.
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