My local gun store has a 1301 comp but only in the 24" barrel version, I haven't found any at any place with the 21" barrel.
And the Tacs they have are the Gen 2s with the threaded chokes.
I got the 24" comp. It's a beauty and eats everything I feed it. The Comp version is build on a 3.5" receiver with the loading port milled out to aid in faster reloading but could use some more relief. The second gen has relocated the serial number (originally located just above the loading port) so that if you wanted even more aggressive work done on the loading port, you could do so. They also have an extended lifter on the gen 2.
I've no probs with the 24" over a 21" barrel.



























