I just wanted to know if anyone has or had one and what they thought about it? I am not certain if it comes in a .40cal but I thought that being the lighter of the two it would give good distance.
I just visited www.hkpro.com and there was all types of things but I have been looking at one of these for a long time and just never knew anyone that had it.
tell all , the novice

The USC is a .45 only.  It is a great little carbine if you can get use to the fugly stock.  You can modify them to no end but since they are no longer imported I left mine stock. And since I bought it for collecting more than shooting it made since to leave it in factory condition.  It is a highly accurate little carbine that is worthy of the HK name if you can disregard the stock.  A UMP it is not but it is still a fine little firearm that I think most people would be perfectly happy with.  Just do not expect it to be a long range sniper rifle.  I have seen posts of people disappointed in the rifle because they put a scope on it and it would not print on paper at 150-200 yards when it had a 50 or 100 yard zero.  You only gain a few fps with the longer 16 inch barrel so it is not going to turn the .45 ACP into a long range target rifle.

What capacity mags were available from HK for law enforcement, and are any in that capacity available for civilian purchase now, and at what price?