Rail Holster for Picatinny and HK USP Rail

An experiment in holster design. 

For HK USP Rail: (HKUSPRail) Print two of the rail adapters, but mirror one of them in Prusa Slicer (or whatever you use). The rail adapter fits the proprietary rail on older USP pistols. Provides a modern standard rail for accessories. Use 3mm by 8mm screws to clamp together.

For Picatinny Rail: (Pic2PicRail) The rail adapter has two holes that line up well with sampled pistols. Use the apropriate one. On one pistol with a slightly non-standard rail.  I softened the adapter with a heat gun to slide on and fit. On a standard rail, it's a snug firm fit. The screw is to prevent sliding. 

Holes at top of the holster fit Safariland and other holster paddles with a 32mm spacing. I like their paddles, but have also included a belt clip. Sized for using common T-nuts and screws for holsters. My experiments show it works best printed as shown in the picture of the print bed. The layer lines are in their best position for the stress.

The holster NEEDS two 3mm x 40mm machine screws and nuts in the holes for high stress use. 

Have used both PCTG and PCTG-CF for the rail adapter. I like PCTG for the holster. The flex (non-CF) in the holster seems to help. 100% fill with 8+ walls. 

Disclaimer: This works for my uses. I haven't figured out a retention method I like. A "hook and loop" strap works.  Suitable for testing and range, works well with things on the barrel that don't work in typical holsters like suppressors. YMMV. Use at your own risk.