I have a Remington Spartan 453 gas operatied semi-auto that I use for hunting. It has been very reliable and will handle 2 3/4 - 3 1/2 in shells. I have found that the Tacstar mag exstention will work on this gun and give a 9 round capacity. They are reasonably priced and I have thought of picking up another for home defense and cutting the barrel to 20" from 26. Has anyone cut down a semi-auto barrel and will cutting the barrel affect cycling?