The mag tube extension I have is a tac star bought it at bass pro and did the spring because it didn't have enough tension with the spring that came with the extension but it works flawlessly now and I'm super pleased and now that I've done the work it cycles as well as my Benelli and that is...
You have to Dremel the crimp off to make the extension work I bought my follower and spring from brownells I think it was 31$ with shipping for both. It made a huge difference and tristar wont tell you anything because it's an imported firearm and they aren't legally allowed to modify them bit...
I also have one of these, I love it. I took the gun apart and polished all of the parts I could and after this thing shot like a champ. I initially used the spring from the extension that I got bit it didn't want to feed the last round after I bought a Wolff sprin and a better follower I haven't...