Unless you are going to use that shotgun for hunting upland birds or ducks and geese, there is no reason to worry about the choke. The choke is in the last 2 or 3 inches of a shotgun barrel. After you cut it off the actual choke will be gone, but it will still be what is known as a cylinder bore choke, which means your shot will spread sooner than it would if the same shell was fired through a full choke barrel. It will still work fine for slugs or double ought buck shot, just won't be great for hunting anything except Quail. It will work for that if you use small shot like 7-1/2 or 9's. Don't give any thought to the barrel splitting, out of over 20 barrels I've cut off, I've never seen that happen. If you want to re-install the front sight, before you cut off the barrel, get a length of thread and a piece of tape. Tape the end of the thread to the receiver where you would expect to find a rear sight if one were used. Gently pull the tape toward the front sight bead and make a wrap around the bead. Pull the thread back to the receiver and place it under the tape, beside the other end of the thread, pull them both tight before you tape them back down. Get a sharp center punch and place it between the two threads at a point 18-1/4" from the front of the bolt in the receiver. Strike it with a hammer hard enough to make an indentation in the metal, saw the barrel off at about 18-1/2", or at a rib support if the gun has a ventilated rib.
