Hey Jeff, why not just get another barrel. I have an 18 inch barrel for mine and a second 18 inch barrel with sights. I bought it from that big catalog gun parts company. They are also online. Name might be gun parts, I don't remember, but they have a lot of stuff. You can change the barrel in nothing flat.
here is a search link on numrich gun parts. Lots of barrels.
http://www.e-gunparts.com/search_beta.asp
Category: Mossberg
Model: 12 GAUGE BARRELS
Item #49720 - Barrel Assembly* $90.85 Out of Stock
Category: Mossberg
Model: 12 GAUGE BARRELS
Item #806130 - Barrel, 12 Ga. $49.65
Category: Mossberg
Model: 12 GAUGE BARRELS
Item #799460 - Barrel, 12 Ga.* $45.45
Category: Mossberg
Model: 12 GAUGE BARRELS
Item #385990B - Barrel, 12 Ga., 18'', 2 3/4'' Chamber, Cylinder Bore, Bead Sight, Blue $59.10
Category: Mossberg
Model: 12 GAUGE BARRELS
Item #386010B - Barrel, 12 Ga., 20'', 2 3/4'' Chamber, Cylinder Bore, Bead Sight, Blue $59.10
Category: Mossberg
Model: 12 GAUGE BARRELS
Item #386000B - Barrel, 12 Ga., 20'', 2 3/4'' Chamber, Slug, Rifle Sights, Parkerized $59.10
Category: Mossberg
Model: 12 GAUGE BARRELS
Item #955080 - Barrel, 12 Ga., 24" Trophy Slugster Accu-Choke $99.00
Category: Mossberg
Model: 12 GAUGE BARRELS
Item #702790 - Barrel, 12 Ga., 24'', Rifled Slug - Original, 2 3/4 Or 3". Blue w/ Rifle Sights* $182.35 Out of Stock
Category: Mossberg
Model: 12 GAUGE BARRELS
Item #702800 - Barrel, 12 Ga., 28'', Vent Rib, 2-3/4 Or 3" Shells - Original Accu Set* $187.85 Out of Stock
Category: Mossberg
Model: 12 GAUGE BARRELS
Item #726090A - Barrel, 12 Ga., Budget, Slug, 18-1/2'', 2-3/4'' & 3'' Chamber. $28.35 Out of Stock
Category: Mossberg
Model: 12 GAUGE BARRELS
Item #799450 - Barrel, 12 Ga., C-Lect Choke $45.45
Category: Mossberg
Model: 12 GAUGE BARRELS
Item #40280 - Barrel, 12 Ga., C-Lect Choke $49.65
Category: Mossberg
Model: 12 GAUGE BARRELS
Item #806220 - Barrel, 12 Ga., Full Choke $49.65
Category: Mossberg
Model: 12 GAUGE BARRELS
Item #706580 - Barrel, 12 Ga., Parkerized $130.50
Category: Mossberg
Model: 12 GAUGE BARRELS
Item #804110 - Barrel, 38'', Full Choke $55.10 Out of Stock
Category: Mossberg
Model: 12 GAUGE BARRELS
Item #594250-02 - Folding Stock, Forend & Barrel, 2-3/4'' Chamber, 18'', Ready To Install. Blue. $153.25 Out of Stock