Sir; Any number of gunsmiths could do that. Barrel wall thickness has pretty much nothing to do with opening chokes. May I suggest to you to try some different shells to achieve your aim, rather than messing with the chokes? You aren't asking for all that much of a change. If you go ahead, find a barrel guy that alters chokes from the breech rather than the muzzle. Jim Eyster in Ohio is a skilled barrel man, Heritage Gunsmiths. Good luck to you.

Socialism is almost the worst.