I have recently purchased a very nice .458 WM (
https://www.africahunting.com/threads/custom-rifle-ranch-458-win-mag.90030/ ) , and have been shooting it a bit zeroing iron sights that I installed. I love the rifle, and feel it is built correctly for a big bore. It has a wide comb that rises slightly to the rear, a wide butt, weighted 10 pounds with scope, a bit over 9 without scope. LOP is correct for me as far as I can tell (matches most every other rifle I shoot). I shoot it well, and can shoot it comfortably EXCEPT that I get a mild headache after a few rounds that lingers for days. It is really ruining my fun. I am a bit worried about long term health effects of shooting it. I have only shot it from the standing position off a barricade or sticks, not from bench. I am preparing for a 2026 buff and elephant hunt, shooting a 450 grain bullet at a chronoed 2310 FPS, with a recoil energy of 64 ft/lbs. Not insignificant, but not nearly as heavy as some of the real big boys. I have been shooting it with four cartridges in trap in buttstock, so weight is about 10 pounds without scope. I am probably an average sized 50 year old, 5' 11" 170 pounds.
The stock is not smacking my cheek, my shoulder doesn't have any issues, it seems the headache is caused by the recoil energy delivered causing rapid skull movement. I have seen CTE, retina detachment, etc mentioned in discussing big bore rifles, but nothing detailed or really much in the way of avoiding it. I imagine it is possible that I have some sort of medical condition that would exacerbate this problem, but I have had brain scans in the past which showed no issues. The last such scan was following a concussion a few years back, maybe prior concussions are to blame in the cumulative effect.
So what do the big bore experts here say ? Is this just something that goes with the territory with big rifles ? Am I an outlier in getting headaches from recoil ? What can I do to avoid this issue other than being satisfied with shooting and hunting with my 375s ? Running numbers in a recoil calculator shows that if the rifle weighs two pounds more, 12 pounds, the recoil energy drops to about 53 ft/lbs, a fair reduction. I have prepared 4 cartridges filled with lead that weigh nearly a pound to put in buttstock while shooting. I have considered adding a tungsten weight inletted under the barrel in forearm to add another pound. This would give me a 12 pound rifle for practicing, and a bit over 11 while hunting with actual cartridges in buttstock. Would a strap on wearable pad help with this aspect of the effects of recoil ? I have never used a shoulder pad, and assumed that they primarily help with shoulder discomfort which is not my issue. I will not use a lead sled, In my opinion they are pointless because the point of impact shifts, they do not replicate field positions, and they are very hard on stocks. I have heard positive things about the Edwards recoil reducers, but I cant install one in this rifle because of the cartridge trap in butt.
I know of a local hunter who hunted/hunts in Africa that did experience a brain injury with symptoms similar to a stroke attributed to firing big rifles, I am uncertain of the cartridge but from talking with his friend assumed it was something a lot bigger than a 458 Winchester. Last year I did fire one round from my PHs Krieghoff 500 NE, killing a zebra, and did not notice any issues.
I would welcome all thoughts, anecdotes, first hand accounts, etc dealing with injuries from recoil or ways to mitigate the risk. I really want to shoot and hunt with this rifle, but not at the expense of my health.
kevinscatalog.com
) I had to move a lot of guns that gave me headaches after a few shots. It seemed what caused the migraines had as much to do with the gun as the recoil. Rigby Big Game in 416 (with real recoil pad added) no problems. Browning A Bolt in 30-06 or 300 win mag, Merkel 500 NE, VC 450-400 NE? Sick for the rest of the day. 
