I assume this bulge is uniform all the way around?
Check the finished cartridge dimensions against SAAMI specs. I suspect you'll find that the bulge is within spec and the case is being sized small enough that seating the bullet is pushing it back out, creating the bulge. If so, it's normal and you're fine.
Still happily answering to the call-sign Peetza.
The problem, as you so eloquently put it, is choice.
He is no fool who gives what he can not keep to gain what he can not lose.
-Jim Eliott, paraphrasing Philip Henry.