The rivet must sit tight and flat in the hole before you pull it. There's little tolerance for over and undersized holes, or a rivet that sits crooked in the hole. My ATS pneumatic puller struggled with them. I talked to the ATS rep at OSH who said their puller is not approved for Cherrymax rivets. But, he said if you make a little adjustment inside the nosepiece you can change how it pulls. I have placed hundreds with the ATS gun since then, at 60 PSI.
AirCam under construction.
Cameron Park, CA (O61)