Iron,
I can't make sense of this brenneke slug stuff. On paper, they are the maximum. They are the ultimate 12 gauge fodder. I witnessed this:

Individual who only owned a 12 gauge pump, shoots massive bull moose square in the neck at about 35-40 yds away with brenneke black magic. Bull drops motionless, guy sets down shotgun. Bull jumps up and bolts like a sprint racer. 2 HOURS later, guy catches up to bedded down bull. Finished off with a handgun as bull slowly rises to continue his death march.

Iron, I have skiny Indian fingers. That slug hit four fingers-width from behind the ear. So about 3.5 inches lower than behind ear. Blood everywhere, slug left clean nickel sized exit hole.

Two things happened immediately: I lost faith in neck shots on large game.

I began to question the mighty brenneke.

I will say this: I don't understand what the heck happened there.

Was the spirit and willpower of the big bull so tough, that he fought for his life?

Was it more mechanical, in that the slug missed an artery or bone?