People are different.
The MSG in one Dorito snack chip will set off a migraine in some people.
Likely same with the whiff of gunpowder fumes, nitrates and nitrites in food also cause migraines in some.
I suspect it is a cerebral vascular sensitivity to various stimuli that causes the "gun headache."
Concussive sound waves transmitted to vessels in head might be a trigger too, in some folks, not all.
The full blown "concussion syndrome" of brain bouncing off skull need not occur to get a gun headache.
But if it does occur, some folks are more susceptible to that too.
The outsides of our skulls are different.
Some of us have a pronounced inion at the back of the skull, a bony prominence, feel it when petting your favorite hound.
Other folks have smooth skulls at the back.
The pseudo-science of phrenology read bumps on the skull.
Maybe insides of skulls are different too.
Some skulls handle brain bounce better.
I only got gun headache from the likes of +.50-cal sporting rifles and the 12ga From Hell 3.85" rifle with 1400-gr slugs at 1400 fps (no brake) to 1800 fps (with brake),
Those are also the guns that caused a mild electrical shock sensation to run down my arm, from shoulder to trigger hand.
That one is easy to explain as a love tap on the brachial plexus nerves in the shoulder,
not as painful as a "funny bone" contusion of the ulnar nerve.
I am lucky in just not getting headaches.
The only other times I can think of mild headaches I have had is after a punch to my face in a boxing match made me suddenly sit down hard on my butt.
Fight was over, I was 17 y.o. and have not boxed since, just don't have the speed some do.
I am a slow-twitch endurance athlete type.
I am proudest of 2 miles in 9:25 at age 18 y.o., back when I was an inch taller and 60 pounds lighter.
Also, I tried learning to ski at 60 y.o. Bad idea. Bouncing my helmeted head off the ice one time was enough.
Had a mild headache for a few minutes after that too. Never tried skiing again.
Now the real funny:
Mr. buckstix once argued that a steel plate on a shotgun-style butt was excellent on a hard kicker, better than any recoil pad.
I am calling out Mr. buckstix on that. Wrong.
As Bob Mitchell noted, a benchrest pad of high-density foam rubber, cut from a deer stand seat cushion,
would work well on a .577 Tyrannosaur with a steel butt plate.
I use such a sissy pad for benchrest shooting.
The extra LOP it gives also prevents Weatherby Eyebrow, at the benchrest.
Accept the scope's ER and tunnel vision at the benchrest.
Learn and live.
