If you can feel the threads, there is no choke tube in your barrel. The interior of the muzzle is threaded to accept a choke tube. You have to insert the choke tube into the barrel and screw it in. The fact that you pattern spread so much at close range, also indicates you have no choke tube. If none came with the gun, you need to go out and buy a couple. By the way, don't use your gun without a choke tube in it. If you wreck those threads or dent the thin barrel wall at the muzzle, you'll never get a tube in.