A .44 magnum refers to a cartridge, or to the chamber of a firearm, where .429" refers to the caliber, and "perfect" is unreasonably optimistic.
All firearm choices are something of a compromise, which seeks perfection, but for which perfection remains elusive. A balance is always sought between portability, trajectory, power, and a degree of useful accuracy. My preference leans towards handy, short, and light bolt action carbines, chambered for what I like to refer to as general purpose hunting cartridges. Not all of my hunting rifles fit that vision, but then not all are intended as general purpose tools. While my definition of a general purpose cartridge may seem arbitrary by some, particularly since it omits the excellent 6mms and quarter bores, I consider high velocity small bores, loaded with light bullets as niche cartridges, rather than among those suitable for all thin skinned game, under all conditions. Therefore my lower limit for a general purpose hunting cartridge are the 6.5 service cartridges, and the upper limit the big case .375s, even though an argument can be made for the .416s. Velocity and accuracy must be sufficient to facilitate 300 yard shots without need of more than a foot of holdover, where a competent marksman can ensure his hits land within 3" of the intended point of impact, or 2 MOA.
In the context of black bear hunting, the general purpose rifle, provides a better chance of success than a rifle or shotgun that's useful only for use across bowhunting ranges. The reason for this is that today's black bear habitat is often impacted by human activity. Thus not only are there the natural openings due to lakes, swamps, muskeg, rivers, and burns, but there are also areas that have been logged, powerlines, and roads built for development purposes, and subsequently abandoned. These areas provide opportunities to see game a greater range than is usually considered. If hunting over bait, almost anything will do, but still hunting requires something with greater reach, that delivers a decisive blow at the limits of its range. As a youngster, I considered this and thought a .350 magnum carbine perfect, but while a viable choice, it did nothing better than any number of similar options; nothing is perfect, but that shouldn't stop us from trying.