The file 'M870 Front Picatinny Rail – Airsoft 3D Printer Model' is (stl) file type, size is 117.1KB.
Thanks to Uncle___Ben for his original design
It's a great start but unfortunately it was a bit small and stuck out on the front way too much for my liking so I went into tinkercad and remixed a flipped around, longer and less obtrusive design you see attached there.
I printed with 50% infill and rotated it 90 degrees so the picatinny rail is facing upwards. I used supports but it depends on how good your printer is at overhang
Edit: I've added 45° offset rails (in both left and right configuration) with a small sight post at the front
M870_rail_45_left.stl | 160.1KB | |
M870_rail_45_right.stl | 159.9KB | |
M870_top_rail.stl | 63.9KB |