You currently have a 28" vent rib bbl. with chokes.
You are wanting a 20" bbl.
Your gunsmith charges $80 to shorten your bbl. and inst. sight.
question: does that include having bbl threaded for chokes as well?
New OEM bbl. is $130-up.
If the answer to the question is 'no', then I would sell/trade your existing bbl. for a shorter bbl. (new or used) in the configuration I wanted. Your existing bbl in good shape will most likely bring around $80-$100.
If you cut your existing bbl. and do nothing else as far as a choke goes, you will then have a smoothbore, 20" bbl with an OC. Same as a slug bbl.
So you could take your existing bbl. and trade it most likely even up on a used slug bbl. that has rifle sights and no vent rib. Don't know about your area but around here used 870 smoothbore 'slug' bbls are readily available at around $100.
Last edited by shortwave; September 17, 2013 at 10:38 PM.