Brileys in Houston, Texas does it. I sent my 302 barrel to them and they did the job and supplied 3 chokes for C$224.75 including insurance and express mail. Go to their website or phone them at 800-331-5718.
BTW I notice you're from Canada, I have an extra Beretta 303 barrel with 3 screw-in chokes (F,M,IC) that I will sell for C$400.00. If you're interested e-mail me at
[email protected]. Regards.