I just picked up brand new 20 ga Mossberg 1000 or Smith & Wesson 1000 pretty much the same gun. What I'm wanting to do is get a few more shells in it for shooting more clay pigeons without loading everytime. The dilemma is not being able to find an extender for it. If you know of a tube that has same threads or did the same thing to yours let me know. Any input is appreciated. Thanks and good day.