Thanks for the replies.
I called and talked to Big Horn Armory (Bryon) and asked about barrel length. To me the rifle would "look" better with a 20 or 22" barrel. He said they have found that 18" maximizes the cartridge and powder burn and said you gain nothing more from a 22" barrel (he said the bullet may actually start to drag and slow down a bit).
I also asked about recoil. He said that the standard loads are like a 20 gauge slug gun and the heavy loads are more like a 12 gauge slug gun.
I am very tempted.
