The Enigma of Dwell Time
By John Simeone
The big fox squirrel had been tormenting my old Basset Hound in the back yard long enough. Each day the squirrel would run up to the sleeping hound, issue a ration of squirrel profanity and then would easily out run the old dog to the big oak tree. There while safely above “Flash” the wonder dog, once again the squirrel would taunt the dog with renewed vigor. There was no way Flash would ever get satisfaction. We use to take him rabbit hunting but he kept high centering on logs in the many clear cuts, his mournful bellows indicating he was stuck again. It would have been embarrassing for many hunters, but you just can't look at a Basset Hound more than 5 minutes without bursting into hysterical laughter. But Flash was my buddy, and he needed to get some pay back.
I figured if I shot the squirrel with a .22 short there would be enough fight left in him to give Flash the satisfaction of making the kill. It was an iron sight shot at about 20 yards, and I aimed for a lung shot loaded with a 22 short hollow point. At the all most negative report there was a much louder “Wonk” sound and the squirrel fell about 5 feet completely limp at the dog's feet. Flash sniffed him once and looked at me, cocking his ear to one side as if to say “Good Shot Oswald.”
My father only knew about one hand gun the 1911, Colt 45 ACP, he said, “Hit a man in the hand and knock him down.” I carried that pistol almost my whole Army career until along came the Beretta, 9mm sorry no thanks.
The little buck just stood there, and Dave Miller already was hauling his out. I leveled the Savage model 99 at 113 yards and made a good lung shot just slightly over center, behind the shoulder, with an exit hole as big as your fist. The buck went down instantly.
I commented to Dave that he was right, the 180 grain Power Point 308 bullet was a better killer than the 150 grain that I had been using, more accurate too. Dave then explained his ballistic theory of “Dwell Time,” simply meaning the bullet stays in the animal longer, sometimes dragging it along somewhat. It deals with three things, The Diameter of the bullet, which is better when it is over .30 caliber. The speed which is good at 2400 fps, but as the caliber goes up the speed can go down and still be very effective. Then there must be a light jacketed bullet of heavier than normal for the caliber.
The bullet hits the animal at a slower speed, but the dwell time inside the animal allows for more expansion of the bullet, transferring more energy to the target. Call it knock down power if you will. This is why I have a lot of faith in Taylor's Knock Out values over standard muzzle energy charts. Sometimes the latter, “ain't necessarily so
So now we know why the squirrel dropped lifeless, now we know why the old slow 45 ACP is still the most popular combat pistol, and why a heavier than normal .30 cal bullet is more effective.
Now we will compare some standard cartridges. Given a range of 50 yards which is a better deer cartridge as far as knock down power, a 243 Winchester TKO 10, a 30-30 Winchester TKO 17,or a carbine in the .44 Remington magnum TKO 27. Field experience tells me the 44 magnum. I bet that was a heart breaker, but all too true. Given the same range with about the same powder charge which has more knock down the 30-06 or the 444 Marlin? You didn't guess it, the answer is the 444 Marlin. That big .429 bullet from 240 to 330 grains puts the DRT on everything you could take with a 30-06. Of course the 30-06 is a fine deer cartridge with a TKO of 21, but if you don't want your buck to make it to the briar patch pack the Marlin, with a TKO of 37
Now for my two favorites the 45-70 Govt. and the 325 WSM. The 325 has both blunt trauma effect and hydrostatic shock, making it a true all round rifle for any North American game with a TKO score of 29. But if you want to make a shot on a moose or elk at close range and you don't want a blood trail, put a 460 grain A-Square Lion Load behind the shoulder with the 45-70 and watch the dust fly when he hits the ground with a TKO of 51. Now that bullet is only going about 1700 fps but as it peels back all the way with its thin jacket inside the big animal there is mass destruction, due to the dwell time.
So it looks like anything with a TKO of 20 on up is going to be decisive on deer sized game. Provided the bullet doesn't zip through with out expanding. With 30-06 class cartridges you are more likely to over penetrate than under penetrate. The 45-70 with my pet 325 grain flex tip Hornady bullet, always goes all the way through deer. According to reports the big 460 grain Lion Load would expand more and penetrate less on a deer with awesome energy transfer.
So looking at TKO in deer class cartridges we have the 243 with a TKO of 10 setting the perfect minimum standard, while it looks like the 30-06 sets the real good standard with a TKO of 21. The 325 sets the all around North American Standard with a score of 29. Then we have the old Army round from 1873 that can out whack them all at close range the 45-70.
Does this mean through away your 7mm/08 oh no its just fine as a deer cartridge. It is part of the hydrostatic shock team of medium fast light recoiling cartridges. Trouble is many hunters try to use a cartridge for something other than what it is designed for. The worst case senerio is using varmit guns like .223s on deer, or a 25-06 on an elk, you may score a few one shot kills, but sooner or later that little bullet will find a way to blow up on the outside of the animal, and then you have trouble.
We know that speed kills in some cartridges if we use the right bullet on the right game. African hunters have found that too much speed can be detrimental, this is the case for the hidden dwell time bullet. The example is with the 416 Rigby, with a 400 grain bullet at 2400 fps. This has perfect dwell time and penetration for heavy game. Taylor said it crumples lions. Weatherby put a belt on the cartridge and made it go 2700 fps, while many a PH said it now lacked the penetration of the older cartridge.
A-square solved the problem with TRIAD, Three different bullets, a monolithic solid that will not deform, a Dead Though soft point with serious controlled expansion with great penetration ability, and last the Loin Load which is my idea of the perfect light game bullet in large caliber guns. This one really expands, while taking full advantage of the Dwell Time factor.
But there is a niche for a light deer rifle with good power. At first there is the 7mm/08 this one is a proven deer rifle in the light version, not too fast and not to much in the kick department. Then there is the 7X30 Waters but not too popular. One of those magical little rounds that does more than what it is supposed to. Then comes the one I'm waiting for that has not been fully developed yet, the 270 Marlin Express, it will be hotter than the 7X30 Waters, and will fit in the Marlin 336 action. Coupled with the Hornady “Leverevalution” ammo it should have both hydrostatic shock and dwell time, making it a fine little deer cartridge …...Pass it on
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