@marcus, cool, i read that most use rivets with XLR's , i just got my rivet gun,
so what size rivets do you use?...i have 4 sizes,
2.4mm. 3.2mm. 4mm. 4.8mm.
With pop rivets it's easy. You want to stick the thick end into the holes you want to join to test fit them and make sure they fit snug. If they're too big you'll never get them in. Too small and they won't expand enough grab anything. Ideally they should just fit snug, very little wiggle room, maybe even require a little push to get them in if it's soft material like aluminum. Steel should have a hair of wiggle room. Do this and then you know you'll get a good joint.
Test fit your drill bit (by hand) in the XLR connector first so that you know that both holes, the existing ones in the connectors, and the new ones you'll be drilling, are going to be the the same size. Choosing the right drill bit for any given rivet size is important.
First time using a pop riveter I recommend snapping a few test rivets into something, some scrap sheet metal or whatever, to get the hang of it. Once you pop a few and get a feel for it you'll be good to go. It's a lot easier than you'd think. Drill thru both piece of scrap, insert a rivet skinny side all the way into the gun, then thick end all the way into the holes, and start squeezing. If one squeeze doesn't *pop* the shaft off, reseat it all the way down and squeeze again. I have the cheapie one with the extended head for XLRs and it takes two squeezes every time.