In my experience the 45 is surely capable of taking whitetail with good shot placement out to 75 yards or so. My experience has been that deer, even with good shots to the vitals, can react differently for a variety of factors. Over the years I have noted that the larger bores will result in a more dramatic knock down and killing effect on deer at a proportionally higher frequency then is reflected by the energy values assigned to the various calibers. There is also a greater margin of error should shot placement or angle present a problem. A few decades ago I ran into a formula developed by John Bell, noted for a vast number of elephants culled in the late 19th century. Using solid projectiles, he noted that energy values did not reflect the “knock-out” characteristics of different bore sizes and developed a formula to better reflect his observations. A 280 caliber driven at high velocity could generate the same energy as a 45 cal driven at lower velocity. Relying on these energy figures alone could get a hunter killed with dangerous game. Taylor’s formula places more emphasis on the projectiles diameter and weight. In the absence of “hydrostatic shock due to the lower velocities of the weapons used, tissue/bone destruction played a greater role in killing effectiveness. Seeing similarities to muzzleloaders using the lead round ball, I tried applying Taylor’s formula to my muzzleloaders, and found them to be more reflective of the results I was observing. His formula is:
[Velocity(FPS) X diameter(inches) X bullet weight(grains) ] divided by 7000(constant) = Taylor Knick Out Value(TKO).
Example for 50cal at 100 yards: [1000FPS X .490” X 177gr ] / 7000 = 12.4 TKO Note: I like a minimum TKO of 10 for whitetail.
The chart below, using my loads for 45,50, and 58 calibers show comparisons at the muzzle and 100 yards, my typical max shooting range. I have included elevation and wind drift values at 100 yards. Note the more pronounced difference of the TKO value compared to FPE in diameter/weight of the round ball. Velocities for all calibers are very close at 1000FPS each due to the combination a the higher BC for a greater diameter ball and the fact that the smaller the ball, the faster they loose velocity. The 54 cal is not included, but it does fall a bout halfway between the 50 and 58 cal.
Perhaps all this is overkill and subject to debate, but I have found Taylor’s formula to present a better reflection of the killing of the various calibers with shots to the vital area. I have seen larger caliber balls will almost always expand, fully penetrate, and produce good blood trails, when the frequent bang-flop didn’t occur. Note in the chart that the 100 yard ballistics of the 58(and 62) cal in terms of drop and wind drift is note much different the faster 45/50 calibers. While the 58 can be driven faster, recoil is excessive, and without much advantage for 100 yard whitetail hunting.
