inrut

Nordic will sell the components seperate but you will probably have to call them to purchase them as components..

All the Nordic tubes are the same thread so the tubes are interchangeable , but you need a different barrel nut for the 870 and m2 but this allows you to change tube length from gun to gun..

I have 2 that fun flawless, knock on wood. I have exploded and seen guys explode the nordic extensions off going into the barrels. If you are really worried try the 48rd lancer mags they seem to be a little stronger, but the surefires work better being shorter when going prone.

Like mark said check out the FSL8's. You can load like a normal 4 shot caddy and as you progress you could also load twins, seems to cover all angles without a upgrade later!!!

Watch the detent in the qd lever as if you get them too tight you will be in the middle of a match and the lever will pop open..