A bulge where the case goes from being solid to open space inside is not unusual
It just means your chamber is a little larger than it could be. Does not mean that it is over Saami spec and is not a sign of beginning of case head separation.
Actually you are lucky in that your die will probably be able to size down the pressure ring area and make for easy chambering. My 280AI chamber is very tight and the die does not size the case body and it gets a little tight in the chamber after the 3rd or 4th firing (and no it is not because of contact at the shoulder).