I don't have my parts yet, but I am reading tutorials to get a handle on things. My plan is to build from a 100% KMP plate. My rivet experience is confined to one AK build.
If the rivets are countersunk on the inside so that the rivet head sits a little below the surface, what keeps the rivet from being loose? Does the rivet head flatten up against the bucking bar and shank metal expand to fill the gap? Hopefully that makes sense.