Compare the legendary killing power of a 160gr 6.5x55 to a 45cal handgun
Yes occasionally I hunt with one of my seven rifles in 6.5x55mm,
as long as nothing big and brown is in the area, since it does not possess enough whammy for dangerous game. Unless you are very lucky or have a back-up shooter.
The TKO formula does have problems, as does obviously whatever program you discovered. It was designed around non-expanding or minimally expanding bullets on dangerous large game.
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Impact velocity at range comes into play. At muzzle velocity the Taylor formula still shows the 6.5x55 in the lead by a good margin over a 45 pistol. Although nailing a 200 pound deer (which would be a huge deer by Alaskan standards) at 10 feet with a 230 grain hardball would probably kill him pretty dead.
But at 100 yards the 45 pistol is only going 650-700 fps
maybe (Taylor TKO of 8-10) while the 160 grain 6.5x55 is going at least 2,350 at 100 yards (TKO of 14)
By the way, I once fired 8 shots of 45 ACP Silvertip HPs into a wounded car struck moose's skull at a range of 6 inches in very rapid succession. None of them penetrated. However after loading some 158 grain metal piercing rounds into my back-up 2.5 inch model 19S&W 357 mag,,,, one clean shot penetrated the skull and put the poor moose out of it's misery.
So bullet construction is also super important.
And there are obvious faults with the Taylor formula when comparing apples to oranges. Since it was never made to take into account pistol rounds compared to rifle rounds.
Now would a Brenneke
solid (not the hollow bowl junk made by US firms) 12 gauge slug at 10 feet have more whammy than a 338 Win Mag at
10 feet...??? Some guides and many Fish and Game outfits think so...
Thus slug-guns for protection while fishing or hiking and rifles for hunting.
While my 338 Win Mag hand-loads throw a 250 grain at 2,650 fps...(TKO of 31 at the muzzle) it is still going around 2,389 fps at 100 yards TKO of 28 and 2,144 fps at 200 yards (semi round nose bullet) with a TKO of 25.
Having chronographed shotgun slugs, I have always found the velocity claims by most manufactures to be rather optimistic. But if you believe Brenneke, their solid slug (608 caliber) would have a muzzle TKO in the mid 50s.
And a paper Ft Pound reading of 2,460 ft pounds.
But at 100 yards, (if you could hit anything) it is only going around 900 fps. with a TKO of around 30 to 35 depending. And of course at 200 yards who knows where it will go..
There are faults with any formula since there are such a wide range of variables. Using an exterior ballistics calculator that claims a 45-70, known for killing Buffalo at extended ranges, is only good for lighter weight critters, does not exactly give you the scientific high ground.