If you want to convert your Mossberg 500A (12 gauge) to a 14” barrel—legally, of course—you will need to order a total of eight front-end parts from Mossberg. Give them a call at 1-800-363-3555 and order one each of the following:

• 13488          Tube Nut 500A/835                                       $8.53
• 11239P         M590/835 Mag Cap Parkerized                       $14.00
• 12410P         Magtube M514 Parkerized                             $38.00
• 12392P         Magazine Spring Retainer 590/835 Parkerized     $3.50
• 12194          Spring, Magazine 835                                    $3.50
• 12359           Forearm, M514                                           $20.00
• 16033P         Bbl Asm 514Bead Hvy/w Parkerized               $100.00
• 12362P         Action Slide Asm 500/514 Parkerized               $22.00

Prices listed above were current on December 7, 2010. Shipping ran me $14.95. So my total was $224.48 shipped.

You can then probably sell your original front end online for anywhere from $75 to $200—and recoup a significant part of your costs of upgrading to the uber-cool 14” front end. All NFA rules apply, of course.