I guess I'm solidly with Darkhorse on vent size. I drill out the vents to .070", some .0075 over 1/16". Perhaps I should get the Bevel Bros. to send me their whitelightnings after they replace them - too bad they get obliterated when changing. Oh well, that happens with the best of the best. On the .45, with it's 'White' Lightning ignition, I think I'll try a 'factory' liner for accuracy off the bench and see what happens. I'll have a 'pin-vice' handy with a .070" if ignition doesn't suit my purposes for offhand, though. I've been able to consistently hold 1" and generally 1/2" with the .40 off the bags & using a .070" vent. My pistol, with it's small J. Bailes lock, greatly increased ignition with a drill-out to .070". I figure sub-3/4" off the bags at 25 yards pretty good for 5 from a .45 pistol! The larger hole doesn't seem to hurt either to .40 nor the pistol.
Thanks for a most excellent produce, Jim.