[Geek44]

A punch and die set (tool and die set) is the way to go but you'll need to part with money if you don't have one. Having said that, they're often very useful so they aren't bad to have. Get a good one if you can so you only need to buy it once. Failing that, I would use McCoy's method. However I would file the sprue or wire...whatever, into a hex shape rather than shave it...but that's just my preference. You can then 'slice' off as many rivets as you need and they'll all be the same.