Knock Down Power
Here I am with a White Super Safari in 504 caliber, shooting a 600 grain Super-Slug over 120 grains Pyrodex-P. Range was 170 yards, shot was taken offhand. The bullet ranged from high on the right rear ribs, forward and down through the huge vessels of the heart and lungs for an instant kill. The bullet expanded to about dollar size, traveled through nearly three feet of moose before coming to rest in the muscles between two ribs far forward on the bull’s chest. The bull fell with the impact of the bullet and never wiggled. This is a good example of how effective a big bullet can be. Below are the ballistic reasons why big bullets are so effective.
Ever wondered why those big White bullets slam your game to the ground like they do? Ever wondered why the game shot with short lightweight pistol bullets run a good ways before they finally keel over? I’ve not only been hunting myself for the last 50 years, but have ardently watched as hundreds of game animals have been shot by other hunters on Video. Almost always, they are using the competitors rifles simply because White can’t afford to advertise like they can. Most are also using the popular 250 grain pistol bullet in a saboted 50 caliber rifle, of whatever brand. Few animals are slammed to the ground. Most jump, then run off, only to fall later. Let’s examine the reasons why.
I prepared three rifles with three different loads. The first, illustrated as Trace 1 below, in red, is a 50 caliber rifle loaded with a Hornaday .452 XTP bullet weighing 250 grains and three Pyrodex pellets.
The second, illustrated as trace 2 below, in green, is a 451 caliber rifle loaded with a White 45/40-350 PowerStar weighing 350 grains and 110 grains of Pyrodex P. The lead bullet is 40 caliber.
The third, illustrated below as Trace 3, in blue, is a 504 caliber rifle loaded with a White 460 grain PowerPunch slip-fit bullet and a modest load of 100 grains of 777.
Most of us know that a light bullet that loses velocity rapidly will lose energy even faster. Let’s see how the same loads above perform with energy:
But doesn’t the higher velocity of the 250 grain bullet in trace one give the hunter a real advantage? The holdover should be far less and the shot far easier to make with the higher velocity bullet. No? Isn’t it this factor that we see advertised by the big companies with their new fancy rifles, loading three Pyrodex Pellets and a light , short Pistol bullet.? Lets see just how bad the total bullet drop is, relatively speaking.
The rifles are now sighted in at 150 yards. The chart will show us just how much hold under or over we will need at any specific range.
So the heavier bullets have a decided advantage in energy at extended range, although not within 50-60 yards, while the lighter 250 grain bullet has a slight advantage in holdover when shooting distances at up to 200 yards. However, the real difference in knock down or killing power is not just energy. It is a combination of bullet weight, diameter and velocity. The old TKO formula (Bullet weight X diameter X velocity divided by gravity) yields a constant which compares the effectiveness of various bullets. The Momentum chart below approximates the TKO formula (although not the absolute numbers).
Randy Smith with Gemsbok, downed with a single shot from a 50 caliber SuperSafari loaded with 100 grains Pyrodex P and the 50/45-435 saboted hollow point (BC = .29) at 140 yards. (June 2004, South Africa)
Well, the reasons why the heavier White bullets are slammers while critters run off a ways with light , short, poor BC pistol bullets should be obvious. That, of course, presumes that the shot is good, with multiple organ systems damaged and eventual death more or less guaranteed. If the bullet doesn’t get into the boiler room, it doesn’t matter what the BC, or the Energy, or Velocity or Momentum is. None of them matter much when you miss the mark.