I'm wanting to build a pistol next and want to know are there any known issues with the configuration, any gripes with its functionality. and if it is functional with a side charging handle upper. I'm wanting to put my hollo sight on it, so should i worry about a front site post or is it best to do a front rail gas block with the option of a flip up front sight. Also, is there a weight difference between the free float tube and the free float rail guards.   Is it legal to have a single point sling on it?

bump for the morning people