A buddy of mine has a Mossberg that has been in the closet for the last 5-6 months. he pulled it out for a good cleaning and couldnt get the choke tube out. He finally started getting it and it got really hard...so hard in fact, that he had to get a pipe wrench to finally get it out. The threads were perfect both on the choke tube and the gun. The next tube went in super easy. He put the bad tube up to the barrel and it was a bigger diameter than the barrel.
So what caused this? He has never shot steel shot through the gun, not even once.
