AR308 Bolt Armorer's Block

prusaprinters

<p>I needed an armorer's block to remove the extractor and ejector pins from my AR308's bolt so that I could properly check headspace. Options on the market run $30 or more, so I opted to design and print my own. Although not as strong as one made of steel, it's perfectly adequate for the few times I would need it. As a bonus, the plastic won't mar the bolt or ejector surfaces.</p><p>Features:</p><ul><li>Fit's standard DPMS pattern AR308 bolts, but may also fit a an AR10 bolt (not sure of any dimensional differences between the two)</li><li>Has holes to allow pins to be driven out from both the extractor and ejector.</li><li>M14x1.5 threaded plunger applies pressure to the ejector so that the pin can be removed or replaced.</li><li>Engages bottom bolt lug to prevent rotation of the bolt while removing/installing pins.</li></ul><p>Notes:<br>-I've included three files for the threaded plunger, depending on how the tolerances are for your print. The threaded portion is either 100%, 99%, or 98% of original size (all other dimensions are the same). I found 100% to be a bit tight, 98% to be slightly loose, and 99% to be about perfect.<br>-There is a standard square 1/4" socket hole on the end of the knob that can be used to wear in the threads if needed - use this carefully, or you'll be printing a new plunger.<br>-Apply a bit of oil to the threads and plunger face.<br>-Don't turn the plunger in until the extractor is removed. It won't break anything but, due to the tolerances, the plunger will get cut up on the extractor claw.</p><h3>Print instructions</h3><p>-Print block main body with writing on bed. Print plunger with end of knob on bed.<br>-I recommend supports in the threaded hole to maintain concentricity, but no supports are needed on the plunger.<br>-Material is PETG, although PLA would most likely work.<br>-Printed at .2mm layer height, 3 perimeters, and 40% infill.</p>