It sounds like that "tit" is the sprue. That's normal for Lyman moulds as well as a lot of others. Most people load with the sprue up and centered, for consistency. I don't think it really affects the flight of the bullet much, but consistency is the key to accuracy.
I read somewhere, long ago, that when Colt started marketing their revolvers, they also made and sold moulds to fit them. I don't know if Colt invented the pivoting sprue-cutter, but it was well received by the shooting public and Colt sold a lot of moulds. I remember reading that rifles were sometimes made in calibers to use the balls cast from these moulds. Most of the handmade bullet moulds back then were of the "pliers" or "pincers" configuration, and the sprue had to be whittled off with a knife or some other sort of cutter. Balls for the military were tumbled to obliterate the sprue. I have heard of people rolling balls between heavy steel plates to remove the sprue also. The Colt moulds with their pivoting sprue-cutters were a great innovation and time-saver.
As noted, Lyman moulds leave a projection, or sprue. Lee moulds make a tangential cut, which leaves a little flat spot but no projection. I believe Moose Moulds can be ordered with the cutter configured either way. In any event, the sprue is normal, and won't hurt anything.
Best regards,
Notchy Bob