Had to do a bit of sanding on the picatinny. I may need to revisit the design and shape it up. We just got the Green ABS at the shop and hadn't printed anything with it yet, so I figured, why not a carry handle. The lower nut holes are way too small for the hardware I suggested, I used #6-32, it worked well. The peep sight worked well with the #8-32 Hardware, just make sure to drill it out before you tap it. I think that the green ABS has a larger shrink ratio than the black, which is probably why I was having trouble with it fitting the picatinny. Make one and let me know any troubles you have.