I have had my 835 for a few years and love it. I have mainly used it for duck and goose hunting. Recently I converted it into an HG shotgun. I was able to pick up an 18.5" barrel on GunBroker for $80.00. I added a factory Mossberg "Tactical Cruiser" forend and finished it off with a mag extension from the "Gun Connection".
While not listed on their website, Mossberg does offer the 18.5" barrel on a special order basis. Here is the email response they sent me:
"Thank you for your e-mail. Part# 90823 Description: 835 18.5 CLY BORE
BEAD SIGHT BLUE, Price$110.00 plus the shipping and handling $10.95. You
can shoot slugs, out of this barrel. You can order it from us at
1-800-363-3555".
I also got a pistol grip for it, but I found that the slide release was hard to activate with it.....
Here is what she looked like when I started:
This is how she looks now:
This is the 835 in "Resident Evil/Terminator" mode: