TKO and bullet design: an interesting phenomenon

[makicjf]

I emptied a 4 lbs jug of Unique saturday and decided to play. I set it about one inch into the dirt of my back stop and left the back unsupported. I went back to the 100 yard rest ( ok , fenceline, but its one hundred yards from my berm/backstop and I use it as a rest sometimes) and fired 3 7.62x54r rounds at it. Shooting quick , center mass hold. Dirt flew up but it never moved. I was upset with myself I thought I had missed a kill zone target from a 100 yards 3 times. Emptied the MN, stacked it and went to the target: three holes about 1 1/2 inches apart about 3 inches to the right of center. Good hits. zipped right through the jug and never wiggled it. I then zapped it with 10 7.62x39 from 100, 10 from 75 and emptied the rest walking forward 3 rounds at a time. the last shot was from about 45 yards. Jug was still standing with 33 30 caliber holes in it-- .I went to the house and got the 7 1/2 inch blackhawk and the 260 grain flatnose over 24 of h110- one shot at a hundred yards and it flipped OVER the berm. Same at 75, 50, and the rest at 25. The difference in reaction was amazing.
7.62x54r -148g 2800 fps(ish)-TKO of 18
7.62x39-123 g 2358 (ish)-TKO of 12
45 colt rnfp- 260 grain 1300 fps (ish)-TKO of 21
I grew up hunting with rifled shotgun slugs in Ohio- Bang flops were so common I thoughts thats how deer died.
I was really surprised by the lack of reaction with the lighter rounds zipping along, and comforted ( again) by the powerful reaction caused by the heavier, flat nosed slower slug. I guess I don.t have a point, but am curious what ya'lls expereince has been, which kills better on medium to large game ( not the 7.62x39) and why does the miltary keep going lighter and faster?
Thanks!
Jason

[x101airborne]

The military keeps going lighter and faster because most people cant shoot and the ones that can are Marines.
And this is coming from an Army Soldier, so no flaming me. It is experience, not a wise guy attitude talking. And yes, I did pull Rangemaster duty for a while and have probably ran thousands of troops through Q courses.

[I'll Make Mine]

The reaction of a small, fast rifle bullet in flesh is very, very different from its reaction in two thin layers of plastic, but yes, a fatter bullet will typically have more immediate effect (that's why "expansion" is ballyhooed so broadly with respect to modern rounds -- it lets a .30 pretend to be a .45). Worth noting that it would take me four or five shots just to hit that size target with a revolver at 100 yards (why I don't hunt with my revolver, though it's partly because my sights are set for 25 feet, and that's a lot of hold-over; I can still keep five or six rounds out of a cylinder in a full size silhouette target at that range, which is quite adequate for non-hunting uses). I wouldn't have any trouble punching it with my Mosin at that distance, though...

[makicjf]

That is a good and valid point. With ANY of the rounds mentioned above, if I fill milk jugs with water they pop like a squished grape ( again more splash with the 45 than the 30 caliber rifle rounds-- the 45-70 with a 405 at 1250 ish makes a big splash). The faster pointy rounds zipped through the plastic meating almost no resistance. while the slower speed . heavier weight and big meplat affected a greater area. I have practiced a bunch out to 100 yards with that revolver. A lot. I do not allow myself to practice close range shots or rapid engagement at close range until I hit a long shot. with the shorter bbls its fifty yards, the 7 1/2 its 100. Though i did hit with the little 3 1/2 inch vaquero from 75 yesterday- one just to the right, one just high, third was a clean hit. It just takes consistent steady practice ( and somedays I can't do it)
Jason

[dmize]

Now for a different view of same phenomenon. Shoot a 3/8 steel plate with any 44,45 or 45/70 load you want and then shoot it with a 55 grain VMax at almost 4,000 fps out of a 22-250.

[makicjf]

it will zip right through I am sure

[35remington]

Your test has essentially nothing to do with anything.

Given modern expanding bullets, the rifle rounds fired in your test can be expected to do more tissue damage than most handgun rounds, including the 45 Colt you fired. Physics and kinetic energy and bullet deceleration are at play in any medium that can significantly slow the bullet. Plastic cannot, and the slower fatter handgun bullets knocks the plastic jugs due to larger frontal area, mostly.

TKO as a "killing power" formulae was developed mostly for those that think a heavy bullet with less energy and expansion is a better killer.

While this is doubtful, people will dream up all kinds of things to support their theories, whether justified or not.'

Your 45 Colt load ranks dead last by a considerable margin compared to the rifle cartridges, even the shortie 7.62 X 39, in terms of kinetic energy. The rifle cartridges increase their lead over the 45 Colt the further downrange you go.

You can't carry many heavy cartridges in combat. Weight has a lot to do with what rounds are popular for the ordinary soldier.

[makicjf]

Small and fast or big and slow... I was not really doing a a real experiment, I was simply surprised by the lack of reaction with the lighter rounds. I am not qualified to have a debate upon bullet kinetics, I have always used slower and heavy, thats what we had to use, so I guess the habit stuck. More rounds makes sense to a point, but if it takes to or three to kia an enemy, while one bigger round works have you really gained anything?
Just a thought. While at my first ipsc match a few weeks ago I watched folks hit steel knockdown two or three times with a 9mm. The 45 acp one thwack down. I had 8 rounds they had many more;t yet I used one and they used three to accomplish the same goal. they have more ammo because they needed more rounds to accomplish the same goal. Moreover, were required to focus on the same target longer. Just a thought.

[Epd230]

In a stressful situation like a fire fight, the first thing to go is fine motor skills. Accuracy will suffer. Small, lighter bullets allow for the soldier to carry more. Allows for more rounds down range and a higher probability of a hit. One hit from a 55 gr 22 is better than a miss from a 50 cal.

[Bucking the Tiger]

makicjf, I have seen what you are talking about. I have no engineering of physics degree, but I have observed first hand weight versus speed and my vote is with weight.
I watch fellow shooters hose down plate targets at 100 yards with their AR's and it is ping,ping,ping. Shoot it with 45-70, 405 gr lead, at 950 fps, and it sounds like a church bell.
We have a number of steel plate ranges for handguns, and I have witnessed the same. 9mm and .38 Special are barely moving steel, .45 ACP and .44 Magnum( loaded down) will flip them.
This is not discounting velocity's effect. I have shot a few deer with fast rifles and saw first hand in the Marines a fellow's life leak out of him after being shot with a 5.56.
British officer's during the time the sun never set on the Empire used giant lead revolver rounds to stop natives at short distances instantly.( I know, velocity wasn't an option with black powder)
Having viewed both methods, I will take big bore, big meplat bullets over speed.

[makicjf]

I was within a "buy now" click of picking up a webley for the vary reason you state. Then I realized I would not be able to shoot it enough to feel proficient with it. I went with a 625 jm instead. `Right now I'm chunkin 260 grain rnfp punkins at about 800 fps. I can't figure out why the soft load is hurting my hand between my thumb and picker finger, though.
I have never been in combat; never had anything bigger than a bb gun shot at me ( farm kids can be stupid... don't tell my son we had bb gun wars) so gladly defer to those who have the experience. I was really surprised by the lack of reaction from what I have always considered effective rounds.

[jmort]

The Taylor K.O. formula is a very good predictor of a bullet's effectiveness on dangerous/large game. If you know anything, big non-expanding bullets will penetrate far beyond any "fast" expanding bullet. A .45 Colt with around 1,000 ft lbs will blow the doors off an expanding .375 H&H with 3,500 plus ft lbs, in terms of penetration. On soft targets, human's etc, an expanding .308 will make a mess of the target and are highly effective. On a bear/lion, the .45 Colt will go stem to stern. For a bear/lion, the "hot".45 Colt is a better choice, than a .308, as it will have a higher K.O. value, just as the formula would predict with much less energy. Bullet construction makes a big difference depending on the target.

[DougGuy]

One of the reasons the 5.56 is effective on the battlefield is that if you kill a soldier, that's one shooter out of the fight. If you wound one, and it takes 6 to carry him off, you've effectively taken 7 shooters out of the fight. I don't know who figured out the logic in that one but I am told it works.

Had a bud in Viet Nam being chased by NVA and got away from all of them but one. He laid in a rice paddy and the NVA was standing there looking waiting for him to breathe, soon as he turned his head, up comes the .45 Colt SAA with a barrel full of water and gravel, the shot bulges the barrel horribly but it tipped that NVA right over backwards off the berm. Some of our boys carried their own handloads, they couldn't use a hollowpoint but they would take a file and cut an "X" across the nose, I understand they made an awesome dum-dum as they were called.

[makicjf]

Great story! Its interesting that an infantry soldier would choose to bootleg carry an SAA over an issued 1911. Unless a 1911 was not issued. Though I often carry a single action 45 as a ccw: but I am most certainly not in active combat!
thanks for sharing
Jason

[revolvergeek]

I observed this myself one time when shooting plastic water bottles with a Tokarev and Makarov. The bottles just wiggled slightly when hit with 7.62x25, but went flying when hit with 9x18 (and .38 spl WC loads also). I really thought that I just couldn't hit with the Tokarev and was just shooting around the bottles, but when we walked up to them they were riddled with holes.

Same thing years before when shooting a big chunk of 6x6 post with .223 and then .30-06; my buddy's .223 just drilled holes right through it, but to my profound, deep and lingering satisfaction one round of WWII vintage API .30-06 split the block in half and set it on fire. [smilie=1:

[DougGuy]

Great story! Its interesting that an infantry soldier would choose to bootleg carry an SAA over an issued 1911. Unless a 1911 was not issued. Though I often carry a single action 45 as a ccw: but I am most certainly not in active combat!
thanks for sharing
Jason

If you knew this guy... Likely he had a 1911 and ran it dry. I never heard all of this story but the guy is one illustrious and seriously outside the box character. Okay guy, but you'd certainly be taking your life in your own hands to date his daughter..