OAL is one thing, but position of the shoulder dictates the headspace. Contrary to popular belief, it is not easy to kill a primer. You have not said what the primers looked like after you attempted to fire. A very small indentation may be a sign of excessive headspace preventing the firing pin from getting a good strike on the primer.
In life, strive to take the high road....It offers a better field of fire.
"Robo is right" Fuzzball