FatDaddyVapes has the 2.5 & 3.0 vented screws for $3.99 per 3 pack. I've use the 2.5 to convert a few Stumpy clones. Needed to cut to length and trim the head length with a rotary tool cut off wheel but works perfectly. Or you can simply use the cut off wheel
to cut a slot about half way through down the length of the screw and across the top and bottom. I have done it both ways and they work equally well. The slot method works on the pin in Derringers as well. I have a Derringer from REO and it works as well, but no better than the slotted one. The hole in the center may be more aesthetically pleasing, but the
juice don't care.