Last year I hunted deer exclusively with a Uberti '73 in a .45 Colt; not because I didn't have other deer rifles, but because it was so much fun to shoot and was more accurate than its design suggested it ought to be! I shot two deer, both does; one big and one small with a "home cast" 255gr lead bullet (an added benny). I had complete penetration and anchored both within 10 yards of the shot (fat "meplat"). One was shot at about 65 yards and the other about 50.
I believe that "noted", writer/rancher, Brian Pearce has done a fair amount of research on the strength of the '73 action and has corresponded several times with Uberti's "tech department" on the design, improvements, and testing regarding .357, .44 Mag, and .45 Colt criteria and limits to give highly "credible" advice on "maximum" pressures when loading. He has stated (paraphrasing) that although Uberti markets a .44 mag '73 with factory pressures much higher than recommended for other calibers in that model, it has different steels in "critical" stress areas not present in .44WCF (44/40), .357, or .45 Colt models. With that said, he considers Ken Water's "Pet Loads Level II" for .45 Colt pistols the maximum pressure level for this design, which is about 2500PSI more than the old "Black Power" Level I loads. Considering that most '73's have considerably longer barrels than that used on most pistols, I find that my own 20" barrel will launch a 250 or 255gr lead or jacketed bullet at between 1200 and 1300fps with loads listed for Colt pistol, not Rugers and T/C Contenders. If I use Brian's criteria, I can safely reach 1400fps without much difficulty, although not needed, and find the most difficult reloading criteria is Cartridge Overall Length to work well in the short action of the '73. The 255gr SWC is bigger (wider), heavier, and as fast as a 240gr "pill" out of a .44 Mag ; and since we see many "pistoleros" declare this combination deadly on game much larger than our average Whitetail deer that should be sufficient for most hunting in the "bush". IMHO, there is no reason to try and make the "old" Colt round into a .454, I've done that in a Marlin and when you reach the "max juice" (mine was 1550fps with a 300gr cast bullet) neither trajectory or accuracy was greatly improved over normal hunting distance. This experiment, which turned a mild round into a "mini" 45/70 made a fun shooter a different "animal" altogether. If you want a fun deer and hog gun that will work about as far as you can accurately shoot with iron sights, and is one of the "slickest" actions ever made, the 73 may just be your "Huckleberry" (an apt metaphor by another aficionado of the Tombstone kind on this post).
