YOUR MAX OAL IS WHAT WILL FIT IN YOUR MAG.DONT WORRY ABOUT YOUR CANNELURES,PRESS YOUR BULLET AT MAG OAL.YOU CAN CRIMP IF YOU LIKE. I DONT CRIMP MY RELOADS. IF MAKE YOU FEEL BETTER TO CRIMP THEN DONT STOP CRIMPING. ALWAYS CHECK MAX OAL THAT FIT IN THE BARREL. I BET THE DIFFERENCE IN MAX MAG OAL AND MAX BARREL OAL WILL BE TENS OF THOUSANDS.