DC-17 in several parts, upper and lower sections slide together nicely and have holes allocated for a 6-32 set screw to hold them together. There's a for-end brace I had to print as a separate part, otherwise it printed with supports that were impossible to remove. The knurled end cap slides into the back of the upper, It might take some sanding to remove the supports and layer lines to allow it to fit.
The magazine plate has a hole in it to tap an 8-32x1/2 or shorter countersunk machine screw to allow it to be easily removed if that is desired. It is also friction fit so you could just fill the hole with bondo when you prep to paint or using something simple like tinkerCAD to fill it in before you print if you don't plan on taking it on and off, I thought it would be useful for a battery compartment because I plan on adding an electronic setup.
The trigger v2 has a slightly above 3mm hole to use a 3mm wood dowel because I find printing small pins doesn't work so well. Trigger v1 should work with the provided trigger pin if you don't want to use a wood dowel. Trigger brace solid is installed in the slot right behind the trigger, trigger brace v2 is installed in the slot further aft. Trigger brace solid is there to act as a stop for the trigger, the other is to wrap an elastic band around to provide spring tension on the trigger I used a 1inch diameter band.
This was the first thing I really designed in CAD so it was all a learning process but I'm quite happy with the results and hope to do more soon. Hope you all enjoy!
Update: added magazine v3 and removed magazine v2. Magazine v3 has a better hole to accept a commonly available #8 machine screw
Update: learned some more about modeling for 3D printing, added some champers to upper v7 to hopefully cut down on the amount of supports you need to rip out. If you set your slicer to require more than 45degrees before it generates supports you should have a lot less. Also I separated the barrel and upper
If you`re interested in a Captain Fordo style suppressor I added a threaded barrel to my thingiverse upload to work with a suppressor design made by thingiverse user OofOof