I talked to Thompson Center (Fox Ridge) a few weeks ago and they said they have no plans at this time to offer a 500 Mag barrel. I also talked to Virgina Valley and they accually had 2 barrels on hand ready to ship. I had traded my Smith 500 off and was going to get a 500 mag barrel in rifle form for my Encore. (This is what V. V. had) I might still have the E-mail with price if you want it. I have sold all my brass, bullets, ammo and dies so dont need one now . I do know they charge a little extra for the 500 barrels becouse they have to go to a different barrel maker for the blanks to get a true 50 cal barrel. Hope this helps.
Doug