for me those rivets that you use there are a pain in the butt. I've had some that just would not set.
I took one of the rivets to my local machine shop and had him make me some bolts the same size but with threads on the bottom. Used a nylon lock nut on it and forgot about even trying the rivets ever again. I think he make me 10 for about 15 bucks. Money well spent and the guys that I gave the extra's to also love them!....sorry I don't have two more but just saying. You may have a machine shop buddy!!!