300 Blackout Jig

thingiverse

"Improved" 300 Blackout jig! Based loosely on 300 jig by jmynheir on Thingiverse! I mounted mine on a piece of 2x4 that is attached to a base piece of plywood I screw to the table with 1/4" inserts and hand screws. Makes for a very sturdy platform. I wanted to connect the jig directly to the cutting tool bed, and be able to align it. Made for standard M4 screw to use the cutting tool's alignment nut, with a pointer to help with squaring it. I was able to get it aligned down to 0.1mm side-side. Tapered jig - I added a 0.1mm taper to make the cuts more square than a typical BO jig. Using calipers, I'm able to confirm this jig makes a more squared cut with much less angle. Adjustable - threads in back to use a 1/4" or M5 screw to make incremental adjustments to the cutting length. Cuts above 1.385" without any adjustment, and can be adjusted shorter depending on your needs. Note that published cast trim length is 1.358. Discard tray is optional - the attached pic shows how I put a box around to collect brass shavings. The tray is short enough that you can push the cardboard under the tray.