Basically you just pick a size of pvc cap that suits the bore of your gun. It will likely require some turning down for a proper fit. I found that by chucking up a piece of pvc that the cap fits on I can just pop on one after another by hand and turn them down. I find that I can do it in one pass so no adjustments between caps and no messing with the chuck between caps. The drill stays chucked in the tail stock so it is easy to knock these out at about 1 minute a piece or so once set up.
The ones I have made so far fit 1" EMT and 1.5" EMT barrels. That is using 1/2" and 1" caps respectively. The bolts are 1.5" long 1/2" bolts. You can grind a point on them, but that adds a minute or so to the time it takes to make them.





