It's going to called the Barnes Buster. Here's the info so far from Dave at Barnes:
This is some of the preliminary notes on what the "Buster" will be.
What will be finalized is yet to be determined.
Calibers available mid-2009 (exact weights are unknown for sure until we
build the bullets):
45 caliber for 45 Colt, 454 Casull, 460 S&W (approx 325 gr.)
50 caliber for 500 S&W, 500 Wyoming Express, 500 Special (400 gr.)
45/70 caliber for the 45/70, 450 Marlin & 458 Win Mag (400 gr.)
44 Magnum (275 - 300 gr.)
.44, .45, and .500 calibers for sixguns as well as .45-70 bullets for 45/70,
450 Marlin & 458 Win Mag.
Construction & performance notes:
Offered in heavy weights and designed for situations demanding deep
penetration in bone and muscle. Bullet holds together - no core and jacket
separation.
Maximum penetration for boars, bears, and other large, even dangerous game.
The bullets have a very small pinhole in the nose, which allows them to be
used in handguns for hunting in states that allow non-expanding bullets (in
other words, it's not an armor piercing bullet as defined by BATF).