I've been bodging action camera mounts for my firearms for a while, usually wrapping a helmet mount around the stock but none were ideal. I also tried using the headstrap but that was ridiculously uncomfortable and normally ended up with a headache.
Fortunately i upgraded to a Contour GPS and the goggle strap mount works just aswell on a baseball cap so headview was sorted. If you want to mount directly to your firearm this is the answer though! I've tried it on .22lr, 9mm and .223 rifles and it handles the recoil fine.
HOWEVER, i then tried it on a shotgun, mounted just back from the muzzle and the camera only lasted 4 shots before it unclipped from the mount and went flying! Fortunately i was sitting at the time so the camera didn't go far. I'm sure if you clagged some tape on there too it would hold it but sort of defeats the object!
Not a bad product, and the only dedicated firearm mount i'm aware of, but the camera holder could be upgraded to handle heavier recoil