I've been eyeing the Insight MX-6, which seems like decent bang for the buck, but since the USP uses a proprietary rail design, I don't know if Insight makes one w/ a USP-compatible mount. I also like the Laser Devices MOLAD, but $1600.00 for a light is rather steep. Is there an interface available for the USP that allows a MIL-STD 1913 mountable systems to be clamped to it? This might allow me get one w/ a milspec mount so it can be used on both the primary & the sidearm.

What you need is the HK MKII or the insight M2 both are for the USP pistols. There was a few for sale on the EE or try Ebay. I know there is a fwe over there too. Thanks Arvin

There's a neat little company that operates out of Tuscon, AZ that came across that selfsame problem when the Glocks became so popular with Law Enforcement, and the screaming for the M3/M6 that Glocks use got the loudest.  The answer that they came up with is a rail adapter that goes over the HK rails.  Here's the web address:

http://www.gggaz.com/products/hk_usp.php

And, since the whole point to having a pistol with the tactical light setup on it is to carry it like that, whether as a SWAT officer or somebody with way too much desire to not shoot the bastard they draw down on, here's the web address of a company that makes holsters for the setup:

http://www.blade-tech.com/

I am looking for a bigger pic of just my USPC 40 with M-6 and GG&G original mount. Don Hume made me a leather holster, the  H722 TAC.

Sidearmor also makes a mount.  I have theirs and the newest one from GG&G.  The GG&G is smaller and more slim, but the SideArmor is more robust and holds zero much better.

I finally got my CCW here in IN and carried my USPC  in a Uncle mikes IWB that fits with the mount. The extended rail area isnt very confortable might have to get the new version or probably just a P200 since my mags will work in it.