Why? what's the difference between the old and new 3/8-10 pins?
if you drill and tap the hole properly on the new style pin you get a very snug fit and the threads in the shaft actually contact the minor diameter of the pin almost 100%.you can feel them riding on the minor as you screw it on.
the minor is the flat area in between the threads.they look almost identical to a SW pin,but the fit is better if you drill/bore the right sized hole and tap with the right tap.
if you drill to .312" and tap with a regular tap then the difference will be looks only.i know lots of people will say that it doesn't matter how much wood contact you have in the threads and it might not,but i love the way these pins play and feel.