View Full Version : Lethality metrics

September 22, 1999, 12:43 PM
Those of you who have read the "Anyone hunt with an AR-15?" thread know where I am going :)

I get annoyed whenever I think of the metrics devised and advocated by some states and gun writers. I all fairness, some people just aren't looking at the big picture and are subconciously thinking of, for example, a 150 gr. .30 cal bullet when they claim that some magical number, say 1,500 ft-lbs of energy is required to kill an elk. However, let us shift the focus and look at large, slow bullets. Elmer Keith was a man with great experience in taking large game and his pet .44 Special load sent a 250 gr. Keith-style cast bullet at 1,200 fps from the muzzle. That makes only 799 ft-lbs of energy at the *muzzle*---probably only around 500 or so by the time it connects with some unfortunate animal. And that load *is* verifiably effective. Further more, folks like Paco Kelly and John Linebaugh believe that heavy, large caliber bullets at around 1,200 fps are around ideal for handgun hunting and claim that they appear just as effective as a high-powered, small caliber rifle round such as a .30-06 and they have taken a lot of game. If you ever get the urge, http://www.sixgunner.com/ is the coolest site on the web regarding handgun hunting---check it out!

The point: lethality is not as simple as foot-pounds of energy and, closer to the truth, I felt like yapping from my soapbox :)

I honestly hope that I didn't offend anyone because there's room for more than one opinion and I certainly won't claim infallability (although I would for the Bible :) ).

David Curry

Long Path
September 22, 1999, 03:39 PM
There does seem to be another degree of damage done to a wider swath of tissues-- "hydrostatic shock," they sometimes call it-- that seems to occur with bullets hitting soft tissue at velocities in excess of about 2000 or a bit over, according to some combat physicians. They were thus of the opinion that a really fast small bullet from a rifle and a really fast larger bullet from a rifle made very similar wounds when fired through soft tissue. Such as it was, this was not too far from the truth (*KEEP READING!!!* I'm a bigger-bore man, myself!). A shot to the abdomen ("soft tissue," remember) really isn't that different when one compares hyper-sonic .22 and super or hyper-sonic .30 hits. Problem is, an organic body, human or game or varmint, is not homogenious; it's got bone, cartelidge, air, etc. To push right on through such a heterogenious assortment of structures, the bullet needs to have some mass for momentum, to cause a permanent wound.

Now, in pistols, unless you're talking about the hand-rifles that comprise the Contenders, XP-100's, etc in rifle calibers, you're talking about arms that simply can't get their bullets up to the velocities that elicit that seeming "equalizer" of rifle cartridges, hydrostatic shock. With pistols, some shock can be induced, but much of the tissue displaced by light, fast pistol bullets simply returns to its original configuration, leaving only the bullet path as the permanent wound cavity. This is rather small, of course, with a light, fast bullet with minimal penetration.

Enter to our rescue the proponents of the "B.H.B." (Big Heavy Bullet) philosophy, of which I am a member. This philosophy is only interested in permanent damage done by the initial strike of a large--preferably very blunt and very solid-- bullet to center mass of the target, pushing through whatever it might encounter on its way through.

While there are those who believe in the "magic" of high energy, light bullets moving along mighty swiftly (and in fact you can see some spectacular stops with these, on occasion!), I prefer not to depend upon "magic," but rather on the good ol' sledghammer approach.

BTW, just about all of the states that dissallow pistol calibers that can't maintain a minimum energy at a certain yardage have no problem with bowhunting, in which the arrow's energy never approaches the same energy, right off the bowstring! A medium-heavy, sloooowwww-moving arrow can handily dispatch a 1000 lb bull elk, hit properly, because of its permanent damage done to arrows. Properly constructed handgun bullets of sufficient caliber can penetrate hard structures like bone even easier.


September 22, 1999, 08:42 PM
Well spoken! You know what I like most about large, heavy bullets at relatively low velocity? They deflect less in the nonhomogenous structure of an animal than light, high velocity rounds, making them more predictable. For example, a 420 gr. .475" bullet at 1300 fps is much more likely to go pretty much straight through the rib cage whereas a 55 gr. .224" bullet at 3600 fps is still most likely to punch straight through, but don't be too surprised if it hitting a rib when entering sends it flying over 45 degrees from its previous path. This is usually no big deal, but what the hey---I like predictability! By the way, this deflection is very real. I've only had one notable incidence, and it was a real eye opener. I shot a doe giving me a perfect broadside while feeding at about 150 yards. I shot right her square in the heart-lung area and that bullet deflected upward so sharply that it missed her backbone by only an inch! This was with a .270 Win. firing a 140 gr. Barnes XBT at 3060 fps (chronographed). This was very good in that she dropped instantly, but bad because what if that round had deflected another direction and, in effect, left her gut shot?

I love high power rifles and I am currently building a rifle around a .264" cartridge of my own design (6.5x70mm Longbow) that about duplicates the 6.71mm Lazzeroni Blackbird which has about 10% greater powder capacity than the 6.5mm STW. It should send a 100 gr. bullet along at an honest 4,000 fps from my 30" barrel. I plan on taking it into the field in the years to come along with a .50 AE Desert Eagle lobing flat nosed 350 gr. .500" projectiles at 1,400 fps. Shots under 100 yards get the .50 AE and others get the Longbow. After awhile, maybe I'll be able to draw some conclusions and then I'll just have to face facts whether I like them or not. Until then, I am free to speculate :) :) :)

Oh, before anyone starts in on me about toting a 15 lb. rifle with a 30" barrel into the field along with a 4.5 lb. DE, I'm doing it for the sake of science---not because I'm weird or anything :)

David Curry

Long Path
September 24, 1999, 01:17 AM

What twist rate? 1:10 or better seems to stabilize the 120's better. Just read an article about the .257 STW, and my uncle wants one in the worst way.

Amazing that you received such deflection with the 140 .270! Rather unusual; usually 120 or better holds its direction a little better than that. Just hit a rib, you say? nothing else? I've hit several ribs with 100 grainers at 2800, and never had it happen personally... Yet.


Will you, too, be one who stands in the gap?


September 24, 1999, 07:00 AM
It was very odd! Only time I've ever seen a bullet deflect like that myself.

The twist rate that I will be using is 1:8" with 3 grooves instead of the standard six to releive some of the stress. You need that fast of a twist to stabilize 160 gr. bullets in a .264" bore (a smaller bore requires more spin to stabilize a bullet of a given sectional density). After I am done experimenting with extreme velocity, I will move to what I designed this rifle to shoot: 140-160 gr. bullets. They drift less in the wind and I feel more comfortable with the greater mass.

The .257 STW is a mighty fine cartridge, I can see why your uncle wants one. I thought that at least one manufacturer had started selling guns already so chambered, but I'm not sure. The only reason why I went the .264 route instead of the .257 route is that for some or another, bullet manufacturers don't make anything over 120 gr. for .257's, yet .264's go up to 160 gr. so I felt that the .264 was a little more versatile.

David Curry

September 26, 1999, 10:49 PM
My two cents worth. First off the little bullet, fast bullet, arrow discussions will never end, nor should they. I am fortunate enough to have killed a lot of big game animals with bow, handgun, and rifle.

The last three elk I have killed were with a bow at under 30 yards, one was at eight yards. A "double lung" shot with a bow will kill an elk quickly, a marginal hit and he is gone. I know of guys who are excellent archers who have lost elk that would have been easily recovered if the same hit was made with a 30-06. I am not sure they would have much better luck with a .44 shooting hard cast. Personally, I believe a good broadhead at close range does a lot more damage than I ever did with my .44 shooting 240 grain bullets.

Most of the guides and game wardens I know seem to agree that the weapon that causes them the most problems as far as wounded animals that go unrecovered is a handgun. I disagree, I think a higher per centage of game is lost to archery hunters...but their code keeps them tight lipped about it.

I love my bow, I enjoyed my model 29 Smith, but for the real monster bulls, most folks are best served by the old 30-06.