you could look at it the other way though. was it the ammo or was it the gun? if the fireing pin is weak it may shoot 200 rounds but have 1 that won't go off.

not a big core lokt fan but think about how many rounds they pump out in a year. sooner or later one of those rounds are going to be duds.

also was your ammo brand new? or has it been laying around? it could have picked up residue and you just didn't notice. is your gun older? some times you will find that older guns have weak fireing pins, some new rifles can also have weak fireing pins.