the best thing about the m500 is that you can interchange the barrels for any occasion. i have mine setup for hd/sd it has a phoenix recoil reduction stock (which makes shooting slugs a breeze) and a 18 inch barrel and in just a few minutes i can put on my long barrel and the wood furniture and skeet shoot and when i return home i can tear it down,clean and return it back to my hd/sd shotgun and place it back next to my bed (which takes me about 15 minutes) in time for a cold beer and supper. don't worry about that barrel keep it or cut it down and buy an other barrel to suit your needs and as far as changing the stock set up if you want i can help you with that just pm me ill be more than happy to guide you along. i have less than 300 dollars in mine and it serves many purposes. go to www.cheaperthandirt.com
click where is says Mossberg 500 and look around there they have stocks,barrels and every thing you could wish to find for that Mossberg i promise.