If you buy a quality gooseneck mount you might as well step up to a back up iron sight for around the same cash. The DPMS fixed sight is cheap, the MATECH is plenty reasonable (check eBay), YHM has some a nice A1 and A2 style flip sights for a good price, brightflashlights has them.
Yep, Natchez has a copy of the old Colt style 4X. It has a compensator
( bullet ) for up to 4 or 5 hundred yards. Think it's made by Barska, and
is a sturdy 22 mm tube. The mount is all in one, and attaches to the single
hole in the carry handle. The open sights are visable under the scope mount.
I believe it goes on sale every so often for about $40. I have one on my