A quick part I designed to replace the broken one on my Airsoft A&K masada. The sides are slightly oversized to compensate for shrinkage when printing in ABS, you may have to shrink them (or file them down) if you print in PLA or nylon. No shaving or fililng should be required if you print at 95% scale, it should drop right in and work like a charm.Print in layers of .3mm or less, at an infill of 60% or greater, for best results print at a scale of .95 (95%) Set the support material option to "everywhere" with the threshhold of 20 (so it'll support overhangs), you will have a lot of support material underneath, but it should be easy to remove with a pair of needlenose pliers and gives a good looking final print. Recommended material is Nylon for durability, but it will work in ABS or PLA. My test piece was printed in Hatchbox black ABS at 230C with the bed heated to 110C on a Kossel mini at a layer height of .2mm and 100% infill.