http://www.dzcues.com/modified_pin.html Hope this helps a bit, but it should work. Also the search engine on here is pretty good, Pretty common question :thumbup: also you could ask in the " As the cue maker " section of the forums.
Hi Tom
It really depends on who made the shaft. If it was someone who used a 5/16 hole for the standard 3/8x10 then yes. If it was someone like myself for example, then no, because my hole for the standard is .283. Which is a lot closer to the standards minor of .281.
It can however be easilly modified to fit the flat bottom.