You can send the barrel to T/C, and they will install the correct choke. They may charge you, and again, they may not. What I would do, is wrap it with newsprint, then bubble wrap, or foam, and send it to:
TCA
Farmington Rd.
Rochester, NH,
03867
I would use a flat rate Priority Mail envelope, available at the Post Office. Get a Tracking/delivery confirmation number! That way, It will only cost about $5.25, plus insurance. T/C will contact you, should they choose to charge you for the choke, but it has been my experience that they usually don't, when handled this way. Good luck, and I hope this helps>>>>Bug.