Don't be cavalier about recoil. It can detach your retina's. If your vision goes funny, you have forty minutes give or take IIRC, to get to a doctor or lose your vision permanently as the retina is starved of blood. It usually happens in automobile accidents, but it can happen in much milder circumstances too.
You can get retinal transplants, but they only last a certain number of years, if you find a donor, and then you still have the nightmare of the anti-rejection drugs that are the chemical equivalent of artificial aids to keep your immune system from destroying the foreign tissue.
mmmm.... Tissue!
Bouncing your brain around overly much substantially increases risk for neurogenic disorder later in life. Dementia, early onset alzheimers, all the fun stuff.
It actually makes me wonder if lifelong shotgun shooters have boxer type ailments later in life from the brain pounding. I wouldn't be suprised, but until someone gets the money and the idea to do a double blind study..... we'll never know.