If you are looking at this for tactical and survival, Think about sending the barrel in to Polychoke. You can have a very versatile weapon with a 20" barrel.
"I would not be an old man if I had not been an armed young man." JTJ
Patron Member NRA
"As democracy is perfected, the office of President represents, more and more closely, the inner soul of the people. On some great and glorious day the plain folks of the land will reach their heart's desire at last and the White House will be occupied by a downright fool and complete narcissistic moron."
--- H.L. Mencken, The Baltimore Evening Sun, July 26, 1920