I've determined it all depends on the gun and the width of the firing pin. My revolver NEVER duds on a Federal or anything else. That auto has a very narrow firing pin print on the rim. The revolver has a big, round firing pin that covers a lot of rim area. Really, that one firearm, a Ramline Exactor, is the one gun I have that duds a lot like that on Federal bulk pack. My other guns are pretty reliable with it, only a rare problem and never a problem with that revolver.
Another thing, when I first started carrying my NAA mini revolver, I had it loaded for about a year once, pulled it out to fire the rounds in it and it refused to fire four of 'em. Heat, moisture, the elements are not kind to rimfire ammo and now days I regularly replace the ammo in that little revolver which I always have on me and haven't had that problem since. That little gun is also pretty reliable with Federal bulk pack. If one does dud on a revolver, all you have to do is cock it (or pull the trigger on a DA) to solve the problem. No tap/rack/bang necessary. Of course, .22 isn't really a self defense cartridge, but I do have that little mini revolver on me all day every day as a back up if nothing else. I always have a larger caliber gun on me, though, too.
