I have swapped out different 500 Barrels in the same gauge. The one warning I will give you. A few years back a guy came to me with a 500 with a slug barrel. That he could not get any elevation on. Well it turned out. Instead of turning out the Tube to meet the barrel lug.. He had gotten a pair of pliers on the Barrel nut. If you have a gap between the Barrel lug and Tube. Either back the tube out. Or shim it. That nut is only suppose to be hand tight.
I agree with the hand tighten only. If the barrel nut is too hard to remove one trick you can do is open the action AND MAKE SURE ITS UNLOADED. Then place the recoil pad on the ground, place your palm over the muzzle and push down with one hand while trying to losen the nut at the same time. Mossberg barrels also fit the Maverick 88 gun in 12ga.