There is a sight and mouint that mounts to the handguard, but puts the sight itself out in front of the handguard, and low enough to supposedly get a weld.
I think it is called the "Railway" and is made by C-more, but I am not sure.
I have looked and read a good bit on the PA but have not owned one.
The Bushnell seems the same money, from a big supplier. I dunno.