Grenadier
.375 member
Reged: 20/02/08
Posts: 570
Loc: North of the Columbia, USA
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Re: Views on Taylor Knockout (TKO) Formula
29/05/11 01:13 PM
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Quote:
Since the 375 H&H has long been considered a good cape buffalo and adequate elephant caliber it gives us a starting place:
375 H&H shooting a 300g bullet at 2550 fps: TKO 40 PI 120 KE 4330 416 Rigby shooting a 400g bullet at 2400 fps: TKO 57 PI 124 KE 5115 500 Jeffery shooting a 570g bullet at 2400 fps: TKO 99 PI 112 KE 7288 and just to add to the mix ... 375 Weatherby shooting a 350g bullet at 2550 fps TKO 47 PI 163 KE 5052 I'd love to see the 375 Weatherby Penetration Index validated with some empirical testing. Just some data to think about, no conclusions on my part.
Shouldn't such things be calculated using the velocity of the bullet at the impact range? Art Alphin lists different ranges when discussing his penetration index. Why not for TKO? There is a difference.
For example:
338 Win Mag Federal, 225gr Trophy Bonded TKO @ muzzle = 33 TKO @ 100yds = 30
9.3x74R Win Mag Federal, 286gr Barnes Banded TKO @ muzzle = 35 TKO @ 100yds = 30
458 Lott Federal, 500gr Trophy Bonded TKO @ muzzle = 75 TKO @ 100yds = 66
470 N.E. Federal, 500gr Trophy Bonded TKO @ muzzle = 75 TKO @ 100yds = 63
Tools like TKO, MV, ME, and PI allow us to compare and contrast loads and cartridges. Values in one tool favor one load whereas values in another tool favor another load. Application to the "real world" is useful but limited. Effectiveness on game has to do with many factors, including bullet construction. For example, would it be better to shoot a bear with a soft nose .338 or a solid .458? Another example is the Paradox bullet. It has a high TKO but, because it is soft lead and will deform against hard targets, it does not conform to the "non-deforming" projectile used in Art Alphin's penetration index. Also, The Paradox bullet scores a whopping Thornily Stopping Power Scale value of 298 but, because of bullet construction, it is not recommended against "Hippopotamus, Rhinoceros, Cape Buffalo, or Elephant".
Still, just for fun, .735 Fosbery Paradox bullet, 740gr lead TKO @ muzzle = 81 TKO @ 100yds = 76
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