Mercury is heavy and relatively free-flowing, so effectively the rifle moves backwards with the recoil while the mercury stays where it is, until it hits the end of the enclosed tube. At this point the rifle runs into that weight sitting there, reducing the recoil of the rifle.
Theoretically, this has a greater impact on recoil than would be achieved by the same amount of weight simply being added to the stock.
The argument goes that x-weight added to the mass, slowing acceleration, is not as effective as the original (lighter) mass hitting that same x-weight as an offset to the acceleration.
As I see it, though, there are a couple of things that could reduce this advantage that the mercury weight has over a static weight:
1. The assumption is that the mercury 'hits' the front of the tube as the rifle recoils, but what if you're firing downhill, so the mercury is allready hard up against the front of the tube? In this situation you effectively have a static weight. Or, say on the bench, if the mercury tube inside the stock is sitting flat parallel to the ground, then the mercury will be evenly spread along the bottom of the tube. Some will allready be fully against the front, with the rest a varying distance from the front, resulting in a 'surge' or a 'push' as the rifle recoils. In any case, the advantage that a mercury reducer has over a static weight will vary depending on the position of the rifle when fired.
2. For the full weight of the mercury to affect the recoil, the rifle will have to move sufficiently during recoil for the mercury within the tube to be pressed against the front of it. Obviously, the heavier cartridges will be more likely to gain the full effect of the mercury, as they move more under recoil.
In any case I've been convinced to try one, one of the guys in the big-bore forum said he has them fitted to all his heavy-recoiling rifles, and that they turn 'tigers into pussycats'!!!
I can't wait until it gets here so I can see the difference :grin:
