What do you think about this wide flat HP bullet?

Quote:
Originally Posted by USSR View Post
One of the biggest ballistics fallacies on the internet is, that a bullet that remains in the target has "dumped" all it's energy into the target, as opposed to a bullet that exits the target. Energy is nothing more than a mathematical formula, and this energy formula has never killed anything.

Not a fallacy. When the bullet stops it has spent all it's energy. This is not debatable.
Click to expand...

Here is your energy equation: Energy = (Bullet Weight x Velocity^2) / 450,437. So as you can see, velocity has the greatest impact on producing a high energy number using this formula. Your mistake is equating the number produced from this mathematical equation with it's killing ability. There is no correlation. I have killed deer with the .357 Magnum, which produces a mathematical high energy number due to it's relatively high velocity, and I have killed deer with the .45 Colt which does not generate a mathematical high energy number due to it's relatively low velocity. Despite the much lower mathematical energy number of the .45 Colt, it is a much better killer on deer and deer sized game. A much better formula than the energy formula to use to determine killing ability is the Taylor KO Formula developed by John "Pondoro" Taylor of African big game hunting fame.

TKOF = (m * v * d) / 7000

where m = bullet weight, v = bullet velocity, and d = bullet diameter.

This gives you a much better idea as to killing ability, however, no formula takes into consideration using a hollowpoint bullet with an ill-suited alloy for the speed intended which may result in a lack of penetration. There is a reason why the FBI demands a high level of penetration from loads they issue to their agents, and does not rely on the bullet "stops quickly, dumping all of it's energy in the vitals" theory. Just MHO.

Don
 
"They are intended for the 7.62 but I have 30-30 and 300 blk that they may find their way into."

Please do not do this. The 30-30 needs .308 bullets.

I do not hunt hogs. I will suggest though that you load up some of these bullets and go shoot some hogs. We learn to do by doing!
 
jamaica said:
"They are intended for the 7.62 but I have 30-30 and 300 blk that they may find their way into."

Please do not do this. The 30-30 needs .308 bullets.

I do not hunt hogs. I will suggest though that you load up some of these bullets and go shoot some hogs. We learn to do by doing!
Click to expand...
Not the 30-30 but the 300blk is ok?
I thought that a cast bullet is ok and some seem to prefer a bit oversized?
And what about the early Ruger Mini 30 that Ruger sold with 308 barrels?

Not trying to be a smart ass. Serous questions.
 
I use a 405 grain JSP on hogs that looks similar in shape. Even subsonic it kills them as dead as other rounds. That said a prettty large difference in mass between 405 and 150.

Hogs are varmits here and I’ve killed them with a .22lr (in a trap), I guess if you kill them or just run them from your property, it’s a net win.
 
ammo.crafter said:
Concerned about leading or not grabbing rifling, match BHN to velocity.
Click to expand...

So a shooter has two guns in the same chambering shooting the same lead bullet load. One has a barrel 40% longer than the other. Which one's velocity does he match the BHN to?

As described in detail by Richard Lee in Chapter 10 (p.129) of the second edition of his book Modern Reloading, it is peak pressure that determines when bullet distortion starts to occur for a given BHN. Lee shows that because the Brinnel testing method can be reduced to PSI of indentation force, if your peak chamber pressure never exceeds 1422 psi times the BHN number, regardless of what final velocity you get, the bullet will not undergo pressure distortion. That's very hard compared to what many use in rifles, and there are examples of a bit of deformation actually being beneficial, as when recovering bore obturation after passing through a bore constriction. Elmer Keith, for example, developed the 44 Magnum with BHN 11 bullets, but his pressures were roughly 2½ times higher than Lee's distortion point. So it's not an absolute limit, but one that tells you where bullet distortion will start, and you then have to determine how much of a factor that is for you. For the BHN 12, 16, 18, and 21 bullets commonly advertised, these pressures would be 17,064 psi, 22,752 psi, 25,596 psi, and 29,862 psi, respectively.

The 94:3:3 alloy, if not heat treated, is estimated by the Cast Boolits site calculator to be BHN 12.2. That expanding bullet can't be too hard in order not to be too brittle, but just under 17,350 psi is where it will start to distort from pressure and is where you want to watch for an accuracy decline or a metal fouling increase. It's a pretty low number for a rifle, and even a starting load of Trail Boss makes more pressure, so some distortion is likely unavoidable. About the best you can do is watch for accuracy deterioration as you work the load up.


jamaica said:
Please do not do this. The 30-30 needs .308 bullets.
Click to expand...

As already explained, this is not true of cast bullets. Even for copper jacketed bullets, the SAAMI standard calls for bullet diameters of .306" to .309". Softer lead can easily be funneled into a smaller bore. Indeed, many 45 Colt guns from the 0.454 to 0.451 transition period have 0.451" barrels with 0.456" chamber throats, and bullets at the full 0.456" often shoot most accurately in these guns. Empirical testing has shown many lever guns like lead bullets at 0.002" over groove diameter for best accuracy.
 
Unclenick said:
The 94:3:3 alloy, if not heat treated, is estimated by the Cast Boolits site calculator to be BHN 12.2. That expanding bullet can't be too hard in order not to be too brittle, but just under 17,350 psi is where it will start to distort from pressure and is where you want to watch for an accuracy decline or a metal fouling increase. It's a pretty low number for a rifle, and even a starting load of Trail Boss makes more pressure, so some distortion is likely unavoidable .
Click to expand...

That is pretty low. What about the gas check as a means to prevent or limit leading?

Pressures for potential load using 4895. This is for jacketed bullets.
5a2620e9c7d455157b85219ca94789e2.jpg
 
Lyman's Cast Bullet Handbook lists loads using a 10:1 alloy with gas checks and they publish velocities up to a little more than 2,000 fps at pressures just over 40K.

The 10:1 alloy is a little softer than the Missouri bullet is.

They do not list IMR 4895 or H4895 as a usable powder.

I would normally use IMR 4198 or RL 7.

I think what you have would be doable within limits. I think the 27.0 gr load using H4895 might be a good place to start and end. You could drop the charge weight a couple of grains and have a workable load to start and then check for problems.
 
I don't think I saw a velocity that you intended to use. I think an ordinary pig is going to die when hit by a cast 150 grain bullet at the normal velocity attained by a 30 commie. I'm not sure that the wide open point is a great idea for that particular target, I think that a plain old SWC HP will work just fine. The bullet is designed for rapid opening. That may not work so well at high velocities against those things, but I don't really know. I suspect that you will get full penetration even if it does expand.

Did that dealer have a list of suggested loads and velocities? if so, that is what your answer is.
 
I was about 5 years old, I got home and my mother wanted to know where I had been. I informed her I spent the morning at that place where they kill pigs and cows. She wanted to know how they did it so I filled her in. I told her they killed them with big hammers etc.. After that I had to scratch the packing house off of my list of places to visit. About 13 years later I delivered a brick of 22 long ammo to another packing house.

One day on her way to work she stopped at a rail road crossing and waited for a train. In all appearance it looked like my two older brothers were running the train and they did not get into as much trouble as I did for visiting the packing house.

F. Guffey
 
As mentioned, regardless of whether the kinetic energy of a bullet is 100% retained in a body or passes through, it is simply not sufficient enough to make a big difference. Because of Newton third law, a bullet capable of exercising enough energy to significantly affect a body, will have a reverse and equal reaction against the shooter.
 
kinetic energy is a lousy measure of what physiological damage or injury can occur, at the normal levels of shooting. on a macro scale, a piece of #12 bird shot at near light speed may not even be felt. thats a lot of ke. otoh, a 20 pound hammer at maybe 50 fps, oh, my, that's going to leave a bruise. we bring those levels down to 1-3k fps, 1-500 grains, and using them on flesh and bone, and things are less consistent, we have to add in other factors like bullet design and performance and target material.

if you test out those first examples on an anvil, that piece of bird shot would release energy on a relativistic scale, enough power to blow an entire county off of the map, possibly. That hammer is going to ring like heck.
 
"I thought that a cast bullet is ok and some seem to prefer a bit oversized? "

It is pretty standard to use a cast bullet that is a bit larger that a jacketed bullet is. If shooting .308 in jacketed, then .310 - .311 in cast would be suitable.
 
Quote:
Originally Posted by black_hog_down View Post
http://www.chuckhawks.com/taylor_KO_factor.htm

Thank you for pointing that article out. I was not familiar with the TKOF, but when I looked at the equation, it made no sense at all from a physics perspective.
Click to expand...

Actually, it makes more sense than the standard energy formula, since it takes bullet diameter into consideration and somewhat diminishes the degree to which velocity is considered.

Don
 
nvcnvc said:
Thank you for pointing that article out. I was not familiar with the TKOF, but when I looked at the equation, it made no sense at all from a physics perspective.
Click to expand...



In addition to the article, TKO was intended to compare effectiveness in knocking out elephants shot in the head since they have thick shock absorbing bone sponge. It had no intended purpose for body shots or small/medium game.

That hasn't stopped people from grossly misapplying it. Other elephant hunters such as Bell favored deep penetrating bullets with precision placement in the brain and used heavy for caliber solid bullets in 6.5 and 7 mm among others.
 
Onespeedbiker,

Newton's third law makes the momentum equal and opposite, not energy. Suppose you suspend a 10 pound rifle from strings and shoot a 200-grain bullet from it at 2600 fps. The bullet is 350 times smaller in mass than the rifle, so when the same force accelerates the two in opposite directions for the same amount of time, the rifle ends up going 350 times slower. About 7.4 fps. At that velocity the gun's recoiling energy is about 8.6 ft-lbs. But the bullet's energy at 2600 fps is just a hair over 3000 ft-lbs.

That difference in recoil energy and bullet energy is the main reason why the bullet is much more distructive to the target than recoil is to the shooter. The fact the cross-sectional area of the bullet is smaller than the butt contact area is too small a difference to account for it. That's less obvious when you speak of a pointed bullet and a wide rifle butt plate than it is when you speak of a .22 rimfire fired from a North American Arms mini-revolver with its tiny bird's head grip.
 
Hmm, has anyone here done any testing on the effectiveness of a slower large caliber bullet .vs a faster smaller caliber bullet with a higher calculated energy number? I've killed several deer (which do not fall into the elephant class) with body shots with both the .357 Magnum with a much faster bullet and higher calculated energy number, and the .45 Colt with it's lumbering heavy bullet and lower calculated energy number. No comparison - the .45 Colt put them down with authority. Anybody ever seen what a slow moving .70 caliber 12 gauge slug does with flesh and blood? This is why I say the mathematical energy calculation which over emphasizes velocity and totally disregards caliber has no correlation with actually killing power. Just MHO.

Don
 
Black-hog-down,

You can fire much softer bullets than you'd think. Elmer Keith used first 20:1 lead:tin, and then 16:1 in developing the 44 Remington Magnum. Both are pretty soft compared to alloys with antimony. If you add a gascheck it will prevent gas cutting and deformation of the base. That's critical for accuracy. The nose can still slump under the acceleration, but its less important than the base is to accuracy as long as it doesn't go too far.
 
You must log in or register to reply here.
Back
Top