After looking at my coil sidemount, I realized that other people may want to use something other than a printed plastic thread for their breech. Or, perhaps, use a totally different style of breech, at a much wider variety of angles than exactly 20 degrees down. So I chopped off the elbow and breech, and opened up the riser region so you can use whatever you want as your riser region. I also made two different sizes of internal gas bypass, so you can use either a MAV-2 poppet valve or a high-flow solenoid. Those two differences aside, it is identical to the 3dp coil sidemount I uploaded earlier. You can use it in any single-turret application, from sidemounts to stern guns.
Below is an example of this setup, with a female-threaded breech like the rest of my cannons and a small internal bypass for use with poppets. I didn't bother with any down-angle, but it would be easy to bend the tube a little. The copper tube was sanded and glued in place with an ABS slurry, and the whole assembly brushed in acetone to seal it. Despite the small gas line, it fires quite hard and reliably as fast as I can push the the poppet. And of course for faster firing, you can always use a solenoid and firing buttons on your radio.
As with all cannon designs provided on this website, this design is provided as-is, with no guarantees about performance. My cannons have worked well for me, but I don't know your printer, your material, or your settings. You assume all risks with printing and using this cannon.