yep gotta watch those federal primers they are very sensitive in the 3 years of metallic reloading ive had federal primers go pop in the primer handtool atleast a dozen times now. the first time it happens it really gets ya good though makes the ol' ticker skip a beat or two. funny thing is it happens so rarely I have to say each time its happened its still startles me half to death, just not as bad as the first time it happened. but with fed primers i suppose you should expect it since they say you shouldnt use fed primers in the hand priming tools.