hollow on both ends? why not?
Have heard of the idea, but never saw any. The idea behind a hollow base WC was that a miniscule powder charge would still flare the base of the bullet into the rifling, proividing fine accuracy with a minimal load for target use.
Now, some people (eyes shift rapidly left and right) have been loading the hollow base WC upside down....producing a load with a huge hollow point, and predictable results from the soft lead slug. Massive expansion and very limited penetration.
Others have decried this practice as inherently unsafe, and indeed, if one loads to anywhere near service ammo velocity, it becomes obvious there is a risk. My personal experience with these kinds of loads is that at very low speeds (600fps or so) we have not experienced any problems, and accuracy is more than adequate for short range plinking.
A double ended hollow base wadcutter would seem to allow for the benefit of both, good expansion of the base into the rifling for accuracy, and a huge hollow "point" for expantion in target medium.
The only real risk I see with such a design (assuming the hollow "point" is shallow enought not to risk creating a small lead pipe out of the bullet) is that with a dead soft slug, one must restrict it to mouse fart loads. And of course, someone, somewhere will disregard that restriction and load it heavier, with possibly very bad results.
Also, if one goes to an alloy for bullet material, one loses the bulk of the expansion, even though higher speeds are safely possible. It really becomes a zero sum game rather quickly.
As a defensive round, its use is highly questionable for effectivness. Great exspansion is fine, but insufficient penetration argues against stopping power. Choosing defensive loads that may reach vital organs is choosing poorly. Stepping up the velocity without hardening the slug is asking for trouble, and hardening the slug moves you back into the realm of conventional service ammo, where there are better performing bullets and loads.