Conical and RB penetration?

[paulvallandigham]

It is impossible, which was my point in suggesting it. Because of the different Ballistics Coefficient of the round ball vs. any conical, the conical can always be expected to penetrate further.

I need to be less "subtle". :thumbsup:

 

[GBG]

The question first posted occured to me when chronographing two smokeless loads: a 545grn .458 cal. round nose and a 545grn .715RB, both at 1500fps and cast from WW lead. Pretty fast but possible with heavy BP loads and some guns. Twenty-four inch long, 8 to 10 inch diameter pine fire logs were used for a backstop. The .458RNs penetrated an average of 22" straight down the heartwood, with no deformation. The .715RBs penetrated about 3" getting only a flat spot on the front, and split the logs with wood fibers holding the two halves together. Different terminal performance but I'd have to call it a draw (in wood at least). We were planning a wild hog hunt at the time.

 

[paulvallandigham]

A friend killed his first Wild Hog with a .62 Cal. RB, with a shot to the front of the chest. The ball traveled the lengh of the Boar's body, ending up buried in the ham on the opposite side rear leg. Don calculated that the ball had travel between 30 and 34 inches. It had flattened its nose, but the back end of the ball was still round enough to determine the caliber. The ball struck lungs, heart, stomach, liver, kidneys, and intestines before entering the muscles in the rear leg. The bore never moved from the spot where he was shot. He shook all the time Don was reloading his gun, and as he was aiming the gun to put another shot into him, the Boar slowly dropped to the ground, head down, and was dead. The whole body cavity was awash in blood when they opened him up.

His ball was cast from pure lead, not WWs, and I am sure he was not trying to send it out the barrel at 1500 fps. More like 1100 fps. Your ball will weigh between 1 1/16, and 1 1/8 ozs. With that mass, the ball will travel the length of your boar with anykind of frontal chest hit, too, and then some.

 

[PreglerD]

Hello from Germany,

Pauls description brought it to the point. Not energy or bullet form is responsible for killing, but only the place where the deer is hitten and what the bullet will destroy. So a well placed RB is enough when it destroys the vitals and there normally the loungs are enough and good to hit.During decades only RB's were used and killed many many deers and people.

Regards

Kirrmeister

 

[GBG]

Du bist richtig einschatzen.

 

[longcruise]

The .458RNs penetrated an average of 22" straight down the heartwood, with no deformation. The .715RBs penetrated about 3"

Different terminal performance but I'd have to call it a draw (in wood at least).

I'm not seeing the draw

The thing that is at work here is sectional density. Your .458 has a sectional density of .371 whereas your .715 ball has a sectional density of .152. Higher sectional density will always provide better penetration providing neither projectile expands on target.

 

[GBG]

The .458RN did have more direct penetration in the form of a 1/2" wide by 22" long "wound" channel of pulverized wood. However no damage was done to the surrounding wood, and no .458 ever showed any visible damage to the outside surfaces of the logs. Although the .715RBs only physically penetrated 3" into the front side, the effect of its impact propagated completely thru the logs length and width, splitting all external surfaces including the rear side. One might call that indirect penetration. The only visible damage to logs hit by the .458 was a small entrance hole with the rest being perfectly intact. Damage to the logs hit by RBs was more extensive ( in square or cubic inches) and immediately visible. There was no doubt which target had been hit by which projectile even from some distance away. Both bullet and ball carried the same energy and momentum into the target but delivered them in very different ways. Based on the high school physics equations Force = Mass X Acceleration, Work = Force X Distance, and Force X Time = Mass X Velocity, the .458RN applied a lower force to the target over a longer time and distance. The .715RB applied roughly 7 times as much force to the target albiet for a shorter duration and distance. Conicals (or in this case cylinders) have to physically pass thru the target to do damage while RBs depend on the terrific shock forces delivered to damage surrounding material. The difference might be visualized like being stabbed with a knife verses hit with a hammer. With all this said, I realize wood and tissue are very different materials and react differently to applied forces, but the same basic processes would occur with different magnitudes depending on the density of the target material. If anything liquid filled tissue would transfer shock forces to surrounding material in all directions more efficiently, IMO. Apologies for the length of this reply.

 

[paulvallandigham]

If you ever field dress a deer shot with a round ball, you will find different results. The primary wound channel will be caliber size, and larger as the RB expands. There is no evidence of a secondary wound channel, because the ball is not traveling fast enough to develop the following "cone " off its backside, like a high speed, modern bullet does. When a modern rifle bullet( not RB) hits flesh, it has a small, caliber diameter primary wound channel, and a much larger secondary wound channel, cause by that trailing cone- a vaccuum-- that first pushes aside tissues around the primary wound channel, and then " sucks " the tissues towards the PWC, tearing blood vessels, and organ tisses by that action.

A lot more damage is done with a modern bullet than with a RB. Just check a shoulder shot with a RB, and compare it to one made with any modern bullet. There is far less meat destroyed by the RB, than with the Modern bullet.

What you say about shock also depends on the size of the RB, and the speed at impact. That .458 may not have disturbed much wood, but wood is much tougher than tissue, in humans or animals. Actually, if you cut a cross section of that log you shot with the .458, and looked at the cells through a microscope, you would see lots of signs of damage due to the shock of that bullet. In softer tissues, the shock helps to mash the tissues in to liquid and "hamburger".

I am not trying to put down the shocking power of large caliber RB, or disagreeing with your observations, to the extent they go. I am merely pointing out the difference between your test materials and real living flesh and bone, and also pointing out that because of those differences, a microscope might be better able to allow you to assess the true damage done with that .458 bullet.

BTW, I did this same experiment with a fresh Elm Stump, back when I was about 12 years old. We didn't have any Mler then, but we fired a bullet from a Springfield Trapdoor rifle into that log, and then had to split it apart( talk about hard work!) to find the bullet, and follow the bullet hole channel through the log. The all lead bullet did not mushroom( a surprise for us) but did rub off about 1/8" of lead off the nose, and enough lead off the sides that the recovered bullet was now .43 caliber, but still showed the grease grooves. The base was squeezed a bit, and was no longer square to the length of the bullet, but it could still be stood on end. We measured 13 inches of wood that were penetrated by that slug.

 

[catman]

Here's a 54cal RB over 75gr of 2F @ 42 yards I recovered last week out of a doe, she did NOT get up. I have a 54 cal RB next to it for a comparison.

Powder/patch side:

Hit side:

A side shot to compare:

 

[Idaho Ron]

The .458RN did have more direct penetration in the form of a 1/2" wide by 22" long "wound" channel of pulverized wood. However no damage was done to the surrounding wood, and no .458 ever showed any visible damage to the outside surfaces of the logs. Although the .715RBs only physically penetrated 3" into the front side, the effect of its impact propagated completely thru the logs length and width, splitting all external surfaces including the rear side. One might call that indirect penetration. The only visible damage to logs hit by the .458 was a small entrance hole with the rest being perfectly intact. Damage to the logs hit by RBs was more extensive ( in square or cubic inches) and immediately visible.

I guess we should all be splitting wood with a ball peen hammer. Just make a 3" dent in the wood and the log will split. ROn

 

[Idaho Ron]

If you ever field dress a deer shot with a round ball, you will find different results. The primary wound channel will be caliber size, and larger as the RB expands. There is no evidence of a secondary wound channel,

I agree, :thumbsup: but this statement would also be true for a conical. They just don't have the speed to cause "bloodshot" that an 06 does. The Hornady Great plains bullet that I hit my deer with this year didn't make a massive wound channel. It was about as big as my thumb maybe a little biger, and blew clear through. The bullet entered at the flank and drove forward and out the shoulder. I would guess the penetration was close to 3 feet! The shot was 93 yards. Ron

 

[paulvallandigham]

Ron: We agree. I was comparing the RB to modern bullets. You would have to use a small diameter conical to be able to generate the speed needed to produce that secondary wound channel caused by the vacuum wave behind the base of the bullet, and I don't know any MLing rifle in a caliber small enough, where the amount of powder needed to send a conical at over 2400 fps. is possible, that would not also be very abusing on your shoulder. There are only a few states where there is not a minimum caliber required for deer hunting.

My brother just chronographed a .28 caliber PRB( actually a #2 Buckshot at .27" diameter)at 2400 fps.MV. But neither of us know any small caliber lead bullet that can be sent out that fast. That is why small caliber high velocity bullets tend to have copper jackets!

 

[GBG]

Wood and living tissue are very different materials, thats one reason I posted the original question. I should clarify that the shock I mentioned above is not "hydrostatic shock" produced by modern high speed bullets that rupture individual cells with hydraulic pressure. As Ron said, neither the .458RN or the RB were moving fast enough to do that. The shock I'm refering to is the sudden impact force so great and over a large enough area that it initiates a mechanical failure (cracks,splitting,tearing) of the wood's structure. With the continued addition of the RBs remaining energy, these failures progress into and thru the log. The .458RN could not reach this threshold of force and area. As for microscopic damage, all I can say is that like you, I found the .458 target logs remaining structural strength required lots of hard work, just to get them into the same condition (split) that the RB target logs were already in. In tissue I think the high impact forces may produce Blunt Force Trama. BTF damages tissue on the visible scale like broken bones, torn muscles, snapped tendons, ruptured blood vessels and broken spinal cords. Going to an extreme, with enough mass (baseball bat, sledge hammer...) smaller animals and even humans have been killed by BFT where there was no penetration thru the body. As you said hydostatic shock damage occurs behind the bullet. BFT is projected forward ahead of an object, which is what I think happened to the logs hit by RBs. Im curious if BFT contributes to a large slow RB's killing power being far greater than the ballistics on paper would suggest? Thanks for all the replys, there is no substitute for experience.

 

[tg]

:snore:

 

[Raider2000]

I agree with Zonie in that a big PRB ".495 or larger" within normal muzzleloading ranges is completely sufficient to take most any game on the N.A. continent & even if it is made from pure soft lead the expansion will help in internal damage which is what causes most animals to expire although the larger hole does help in external bleeding.

For long shots beyond 125 yards I would turn to a heavy conical where it's momentum will push it through at those distances.

 

[paulvallandigham]

From the statements of men who have survived being hit with large projectiles in war, (non-exploding rifled grenades, cannon shells, etc.) I am sure that the BFT radiating in front of the large round balls Is like being punched in the gut! I am sure that there is damage done to internal organs even from a Large shotgun slug or RB that does not break the skin for some reason. We have had several hunters survive being hit by shotgun slugs during deer season over the years, most fired from locations and by persons unknown, and the bruising internally, as well as in the flesh is extensive.

If you every use Ballistic's Gel for testing this kind of thing, you will see radiating "cracks " in the blocks ahead of these large diameter balls, too.

 

[ronrryan]

I well recall as a new deer hunter shooting a medium size doe with a 7.65 Mauser at about 20 yards. The entire shoulder was bloodshot meat, had to be cut out. The load was a Norma factory boattail, very frangible jacket (all I could get) and pretty high velocity, probably 2900 at the muzzle. There were little bits of copper and lead all through the boilerroom. All I saw when the rifle came down out of recoil was four feet in the air. When we butchered, my old, knowledgeable hunting mentor said "what the hell did you use, a grenade?" PRB is much nicer for having meat left to eat. Good smoke, Ron

 

[longcruise]

As you said hydostatic shock damage occurs behind the bullet.

You an Paul both have made that statement, but given that it is, at least to me, counter-intuitive, i must ask what is the technical sources, etc that support the wave behind the bullet creating the secondary wound channel.

 

[paulvallandigham]

There are number of high speed photographs of high speed bullets showing that cone behind the base of the bullet, in all kinds of articles. I suspect I have half a dozen articles in old Gun Digests, or in magazine articles I have saved that show it. The photos show a wave coming off the nose of the projectile, regardless of its shape, and with high speed bullets, a second cone coming off the base of the bullet.

The whole reason that " Boat Tail " bullets exist is so that the Drag caused by the cone's vacuum can be reduced by tapering the diameter of the bullet down to a smaller " tail ". Reducing the drag helps the bullet fly flatter, and resist winds better, for long range shooting.

The Builder's of the yacht's for the America's Cup Yacht Race have incorporated the same principle to reduce the drag on their racing boats, so that the boat can sail faster in water. The principle is NOT NEW. The Viking raiding ships had tapers to both the prow, and the stern of the boat, and the design has been used in building small craft, like canoes since pre-historic times. Only the application is " relatively" new.

It was the advent of Nitrocellulose powders, mainly developed by the DuPont Corporation, that allowed small arms to fire bullets fast enough that a boat tail shape became desireable. The U.S. Military began using boat-tails in their .30 caliber match grade ammo back in the 50s, and possibly earlier. The .223 caliber bulllet loaded in the AR-16 rifle issued in Vietnam in the 60s, is the first time such a bullet became issued ammo for general use. More recently, the nower, heavier bullets- 70 grains, and 62 grain .223 bullets-- are boattailed, to give them a better sectional density and longer range accuracy and energy.

 

[longcruise]

There are number of high speed photographs of high speed bullets showing that cone behind the base of the bullet, in all kinds of articles. I suspect I have half a dozen articles in old Gun Digests, or in magazine articles I have saved that show it. The photos show a wave coming off the nose of the projectile, regardless of its shape, and with high speed bullets, a second cone coming off the base of the bullet.

Yes, yes, that is nothing new. You have it backwards though. Both supersonic and subsonic bullets display a wave coming off the nose and the base, however, the pressure wave at the nose is more pronounced in supersonic bullets and the wave off the base more pronounced in subsonic bullets. The wave off the nose is the one that does damage in supersonic bullets. Especially if there is a flat meplat. The nose flat, be it typical to the bullet or to it's expansion causes tissue destruction by sending off a spray of liquified tissue that creates a secondary wound channel. (for further reading on this I refer you to: http://www.fulton-armory.com/fly/

The whole reason that " Boat Tail " bullets exist is so that the Drag caused by the cone's vacuum can be reduced by tapering the diameter of the bullet down to a smaller " tail ".

.......yada yada yada. Common knowledge and largely irrelevant to the discussion at hand.

The .223 caliber bulllet loaded in the AR-16 rifle issued in Vietnam in the 60s, is the first time such a bullet became issued ammo for general use.

Extreme spitzer bullets with boat tails have been used as early as 1895 in the Austro Hungarian Steyr Mannlicher and aslso in the Swiss GP11 ammunition dating to prior to 1911. Those are two that I know of but there are others.