AR15 Bolt Jig

I wanted a simple jig for checking headspace but didn't want to mess with supports or printed threads. All you need is a spare piece of brass and to leave the extractor on. V1 has minor overhangs that fully lock the bolt in place. V2 is just drop-in (the lug supports just help prevent rotation). Both are symmetrical so you don't have to worry about lining things up just right. I might upload updates later (much later) for other calibers but all you have to do is change the supporting area for the casing.

Update: I've been using the later version and it works well, I even advise against using V1 because if a roll pin or something gets stuck halfway out you won't be able to remove the bolt from the jig. I've updated the f3d file so you can simply change the cartridge base diameter under "parameters" to change caliber.

On a side note: the wheeler roll pin punches suck. The metal is too soft and likes to mush on every single punch. I've been using a well-fitting allen wrench I cut the angle off of (don't forget to file those ends flat) and it's worked wonderfully. Even cheap ones are made of a hard steel for the sake of not rounding off.