IvW, you mention more effective ways to reduce recoil than mercury reducers. What do you suggest?
Recoil, there are two types: Actual recoil which is calculated based on the caliber and rifle weight and then perceived or felt recoil.
For some reason bigger folks get hammered harder by the same rifle than smaller folks.
What I would suggest before installing a Mercury recoil reducer.
1. Correct weight for the caliber. A 7lb 375 H&H will recoil more than a 9lb one all else being equal.
2. Balance-the rifle has to be properly balanced.
3. Stock fit-probably one of the most important. Not only will a ill fitting stock cause more perceived recoil but it will also make you shoot bad. Just try hitting flying objects with a shotgun that has a stock that does not fit you. Easy to do when building a custom but not so easy on mass produced rifles that come with standard dimensions.
4. Proper high quality recoil pad.
5. Proper shooting stance-you need to hold a big bore correctly, standing too far back will result in getting shoved back further, creeping the stock will result in a half moon cut above the eye. Takes practice but goes a long way to reducing felt recoil.
6. Trigger pull should be crisp and not too heavy, if you need to hang onto the trigger to fire the rifle the recoil felt will be more due to the anticipation.
7. Caliber, many people just cannot handle the recoil of DG rifles yet they persist. Some caliber designs will increase recoil velocity. 404 Jeff will produce a lot less felt recoil than a 416 Rigby, therefore a 404 Jeff is preferable to anybody wanting a easily shoot able 400 caliber. The effect on the front side is the same and the animal would not know the difference. The shooter will also be able to place his shot better. Many hunters would be better off with a 404 Jeff than a 416 Rigby...
Some cartridges achieve the same velocity with the same bullet but do so at higher chamber pressure, some significantly higher. Again all this means is that you get the same performance on the front side but with greatly increased recoil.
I honestly believe that many visiting hunters(hunting DG), are too obsessed with velocity and trajectory. The old recipe of a heavy for caliber premium bullet travelling at a reasonable velocity and placed in the right spot will kill every time on DG. This velocity being 2100 to 2300 fps with a max of 2400, anything over that is just greatly increased recoil and wasted.
If after all this the person can still not handle the recoil, step down in caliber or try a milder recoiling one. Try a 404 instead of 416 Rigby or WM or go down to 375 H&H with a heavy bullet at 2300 fps.
Last resort should be some or other inertia recoil reducer.
Muzzle brakes are a big no no on a DG rifle.....