I finally got it on there.....
Turns out the "ears" at the top of the attachment were making contact with the forearm before the nipples where going into the swivel. I took a dremel and flattened the ears out, took just a bit of metal off and then it fit....tight but it fit.
It could have to do with the extra thickness of the truck bed liner I sprayed on the stock but I doubt it.
Seems to be rock solid now.....heres my sniper team checking it out. They need more practice but they are coming along.