Don't cut it. IF S&W doesn't offer one, then you probably won't find one. I doubt seriously there is enough of a market for short barrels for the 500 to justify anyone making one. Also the price of .50 ammo is such that one would have to spend a lot of money training and practicing with the pistol to become sufficiently proficient to 'carry' it regularly - and endure a huge amount of wrist punishment in the process. Actually, my best advice would be to keep this gun for range use, and find yourself another, lighter, smaller caliber firearm for carry. If you're really wanting a short barreled "bear gun", maybe take a look at the Ruger "Alaskan" model in 44mag budsgunshop.com/catalog/product_info.php/products_id/39998/ruger_5303_super_redhawk_alaskan_ksrh-2_6rd_44mag_25 or 454 Casul budsgunshop.com/catalog/product_info.php/products_id/14313/ruger_5301_super_redhawk_alaskan_ksrh-2454_6rd_454cas_25

You are going to increase muzzle blast/rise and recoil significantly with a shorter barrel. New this would be a $1200 purchase minimum. .If it were my revolver and dead set on a shorter barrel I would contact S&W or look for a shorter barrel revolver. Sell the 10.5 bbl 1.