44mag sectional density?

CraigC said:

Some folks obviously don't know what sectional density is or how it might be used to predict penetration when using solid big bore handgun or rifle bullets. When someone says sectional density doesn't matter, what I'm hearing is that weight doesn't matter and we all know that it does. Back when a 430gr .475 was the penetration king, I started looking at the Linebaugh penetration tests to see what the best penetrators had in common. Or what was needed for a .44 or .45 to equal the .475. The answer was bullet weight. A 430gr .475 has a much higher sectional density (~.270) than any of the more common .44/.45 bullets. That is, until we get up to the 355gr .44 and 360gr .45 (~.250). Why was the 430gr the accepted standard for the .475 but not similar bullets for the .44 and .45? Perception. Same reason folks think of the .480 as a heavy bullet vehicle, forgetting that it can get a 275gr deer grenade to over 1700fps. Perception. This is when I began to look at sectional density as a factor in predicting how well a bullet will penetrate. No, it is not a measure of lethality (like energy) and I've never used it as such but it is an important factor in predicting how well a bullet might penetrate and how any given caliber/weight might compare to another. When we're talking "heavy for caliber", we're talking sectional density. SD is simply a way of quantifying a bullets weight relative to its diameter. It puts a number on a concept. It's what separates a 300gr .45 from a 300gr .500. It is how we compare one caliber to another, putting a "how much" on what constitutes "heavy for caliber". It is one of many factors affecting penetration, no more or less important than the others. The others being construction (toughness or lack thereof), nose length/shape and meplat diameter. Momentum is also extremely important and it is the reason why heavier bullets penetrate better than lighter ones. It's also why heavier (high SD) bullets are used in long range shooting. In simplest terms, if you take two bullets of different materials but otherwise identical, one 200gr and the other 300gr, the 300gr will show dramatically deeper penetration. One thing I'll make note of is that weight is more critical with cast bullets because they need the extra momentum as the nose starts to deform. A monometal solid still needs weight to do its job, just not as much because it doesn't deform.

No, I don't think there is a lot of difference between the .44Mag and .454 when solids are used. As I said, the two Buffalo Bore loads referenced are the same pressure, 50,000psi. Which is where most factory .454 loads are. Which lies right in line with the available 50-55,000psi data for the .45Colt and .44Mag. Sure, the .454 can push them faster but at what gain/loss? It is with expanding jacketed bullets that the .454 gains the edge. It's easier to design a bullet that works properly when you have lots of velocity. Which is why if I were going after anything big with A-frames, I'd want something with some speed, like the .454. Which is probably why I have two of them, plus a .450BM. That said, despite the impressive results I've witnessed, I would still prefer the extra insurance a tough solid delivers on dangerous game.

2000fps is the generally accepted threshold where hydro-dynamic shock begins to factor in. There's probably a good reason why all the classic big bore stopping cartridges run around 2100-2200fps.

As far as the .44 being an "underachiever", I think some folks decided a long time ago that the .45 was better and still believe in magic, despite evidence to the contrary. Personally, I think they all do pretty much the same things. The .475's and .500's just offer a little more margin for error and a better chance at stopping the quarry a little more quickly. What it comes down to is the bullet. As long as a +.40 caliber bullet with a wide meplat breaks bones and makes it to the other side, the rest is gravy. The problem is that cartridges like the .41Mag lack the capacity for bullets heavy enough to do the job on very large game. Where a 280gr (SD comparable to a 300gr .44) at 1300fps is about the best you can hope for, the .44 does the same thing with a 330gr. There are NO Punch bullets or Barnes Busters available for the .41. Only the 220gr CEB. The .44 and .45 are where we begin to make strides. Personally, I think the sweet spot is somewhere between the 300gr .44 and 320gr .454 Punch loads. I think the .44Mag or .45Colt loaded somewhere between 40,000 and 50,000psi is about perfect.

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Tradmark said:

Several missteps. Saying something isnt the biggest factor isnt the same as saying it doesnt matter. The point is that it isnt as important as you think it is. U yourself witnessed your own lower sectional density loads pass thru waterbuff when the higher SD cast loads didnt, and neither did the 475’s and 500’s and 500 max rounds.

As far as the 2000 fps magic spot, im not sure where that came from. Wherever it was was in error. Its sooooo wrong its not even funny and been debunked on video many many many times. Pics of wound channels and other evidence point to it being false. So does cracking open a chest in the operating room and seeing the difference bw a 9mm and a 357. Trust me, neither is at 2000fps and there is some hydrostatic shock being produced and causing damage. Its just wrong.

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CraigC said:

It wasn't said that SD wasn't the biggest factor. It was said that:

"I think SD is much ado about nothing"
"Also, monolithic solids render the sectional density argument a bit silly."

I addressed SD as it relates to cast or monolithic solids in my post that you quoted.

As far as "the magic spot", it is something oft repeated by people like OURSELVES that with handguns and solids, it does little good to push bullets beyond 1300fps because there is little terminal yield for the cost you pay in recoil. That hydrodynamic shock doesn't appear to become a factor until somewhere north of 2000fps. So it's news to me that with solids, an extra 100-200fps makes a measurable difference, because you're still a long way from it making much difference. I'm not saying it's critically important but it is what separates handguns and rifles. Whether or not it matters is a topic for another thread.

Don't worry, I'm going to find out what effect velocity has on penetration in the next round of testing.

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Jessesky said:

True but I think the xframe is too impractically large for woods carry which is my purpose. At that point I may as well be carrying a rifle. Would channel is important, but Is the wound channel difference so significant between the 500 and 44 that it makes a difference in a defense situation when only seconds may matter? If you don’t hit a vital with either, most likely it will take too long for the animal to expire for bullet size to matter. Im not saying this is fact, but asking to better my knowledge

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CraigC said:

Some folks obviously don't know what sectional density is or how it might be used to predict penetration when using solid big bore handgun or rifle bullets. When someone says sectional density doesn't matter, what I'm hearing is that weight doesn't matter and we all know that it does. In simplest terms, if you take two bullets of different materials but otherwise identical, one 200gr and the other 300gr, the 300gr will show dramatically deeper penetration. One thing I'll make note of is that weight is more critical with cast bullets because they need the extra momentum as the nose starts to deform. A monometal solid still needs weight to do its job, just not as much because it doesn't deform.

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CraigC said:

You're clearly not reading what I'm writing because you just confirmed what I've been saying but whatever......

CEB has never put much effort into their flat nosed handgun solids. Else they would've given us what we asked for with a larger meplat and an ogival shape, rather than just a truncated cone that was just easier for them to machine. They're primarily rifle guys.

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CraigC said:

You're clearly not reading what I'm writing because you just confirmed what I've been saying but whatever......

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CraigC said:

If the SSK was so great, why don't we still use them? Why do we use LBT's? That is NOT the conversation we have had on the phone about truncated cones. Changing our tune to fit the argument?



And I repeat.

I have said REPEATEDLY that SD was used to compare bullets of similar construction and design, across calibers. I might also point out that this friggin' thread is about CAST bullets. Not copper solids.

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MaxP said:

You are isolating the one instance where SD may matter, when all else (including material and hardness) is equal save for weight. That said, two bullets with the exact same SD won't perform the same with different nose profiles. See where I'm going with this?

Still firmly believe that even with the right bullets the .44 is an underachiever. It will get it done no doubt, but in every instance I have seen them used on big game animals in the 1,400-lb. range, follow up shots fail to impress. While highly "unscientific," the bigger calibers (loaded correctly) just hit harder and tend to put the animal down in more dramatic fashion when good placement is employed.

Craig, I would implore you to work up a good monometal solid load for that .500 JRH you have and use it during next year's bash. You will see exactly what it is we are talking about.

Also, if one is to consider a great all-around expanding bullet, you would be hard pressed to find a better one than the Swift A-frame. That thing is lighting in a bottle on big animals. They don't over-expand and they hold together under the worst conditions. Got to witnessed them used in a couple of different calibers during the Bash this last weekend and they delivered in virtually every case on large animals.

This is the document tradmark referenced in his last post (author is Michael McCourry. His testing included more than 125 buffalo - water and Cape).

There are 8 Absolute Known Factors for Solid Penetration and are as follows in


Order of Importance.....

!

#1 Meplat Percentage of Caliber

Meplats that attain 65% Meplat of Caliber are terminally stable.... Above 70% Meplat
bullets remain stable, however depth of penetration begins to decrease with every step up in
meplat size. 70% Meplat or larger does increase trauma to, and destruction of tissue. 70%
Meplats start to get difficult to feed, even in Winchester M70s...... From 65% Meplat to 68%
Meplat is OPTIMUM for Stability, destruction of tissues, and feed and function in most quality
rifles..........

#2 Nose Profile

There are many and varied Nose Profiles of solids on the market today, from the angled
Nose Profiles of CEB and North Fork, to the straight nose profile of the older North Forks
and GSC, the Barnes/Hornady Profiles (like a RN cut off at the top) to many more... Not all
of these are created equal, and some are better performers than others. In recent tests in
comparison between the old North Fork Profiles and the Newer North Fork Profiles I was
getting 20% deeper penetration with the Newer North Forks than the older, with the same
bullet, just difference in Nose Profile is all.... John at North Fork agrees, and in their work
there they were getting more along the lines of 25% deeper penetration. One major thing
that I noticed here, the stability at the end of penetration was 100% better. In most all tests
here the last 2 inches of penetration of the old style North Forks would be unstable. Now this
is and was of no consequence at the very end of penetration. The depth of penetration of
these older nose profile bullets was always so deep that it had long accomplished its mission
before loss of stability right at the very end. This new NOSE PROFILE of North Forks remains
DEAD STRAIGHT to the very last of penetration, and always found NOSE FORWARD........

#3 Construction & Material

Construction of a solid is a major part of its ability to penetrate. To deny this is foolish to say
the least. Some of our solids out there, lead core, are very very weak in construction and
absolutely do not have the ability to bust through heavy bone and reach their intended
targets. I have seen and have in hand failures of these bullets from the field..... A shame as
well, as some of these bullets are promoted as Dangerous Game Solids, and some of them
flatten out like pancakes when hitting some heavy..... Some FMJ Have steel inserts, while this
solves a problem in one area, it creates problems in other areas.... Brass is harder than
Copper... No surprise there, but I have busted elephant heads with both copper and brass,
and never had one distort, but, these solids were of a very STRONG NOSE PROFILE as
well........ So you see, combinations of different factors work together to strengthen or
weaken other factors..... A good strong Nose Profile, can overcome some material
deficiencies and in the case of copper solids this is extremely important, and very true........

#4 Nose Projection

Nose Projection above the top bands was the last factor discovered. There may be more
factors, but currently they remain undiscovered at this point in time.... We found that nose
projection above the top of the bands of current CNC monolithic bullets is very important to
depth of penetration. Some bullets designed to work through lever action rifles require a
SHORT NOSE PROJECTION in front of the bands so that they can be loaded deep enough to
work through the actions of these guns... Nose Projection of these same bullets for bolt guns,
single shots, and double rifles are longer, from .600 to .700 in front of the top band. The
LONGER NOSE PROJECTION solids will penetrate on average 25% deeper than the shorter
nose projection. Now, these bullets already have all the other required factors for stability,
nose profile, construction and radius, so it is ONLY DEPTH Of penetration that is effected with
properly designed bullets.

#5 Radius Edge of Meplat

We found that the radius edge of the meplat made a difference, small, but a difference none
the less. A nicely radius edge penetrates about 5% deeper, and has more stability at the end
than a sharp edged radius.... No more to go into here, that's it.......

All the Above Factors Deal with Bullet Design........

#6 Velocity

Velocity is a factor, but it also goes hand in hand with Nose Profile and Construction/
Material. If we assume that the Meplat is optimum, the nose projection is optimum, and the
bullet has a nice radius then velocity becomes a factor in combination with nose profile and
construction/materials. Different Nose Profiles react differently with velocity. Some nose
profiles at very low velocity cannot maintain stability, but this would be in the extreme, and
other factors may come into play with some of this. In essence with some Nose Profiles,
added velocity will equate to added depth of penetration, and of course trauma and
destruction of tissue. Some nose profiles react better than others, but if properly designed,
then all will get some gain from added velocity, UNTIL you reach the point that you get
distortion of the meplat by TOO MUCH VELOCITY. Once you begin to distort that meplat,
then all sorts of strange things begin to occur. One is depth of penetration will decrease,
stability will decrease as well....... Normally you will only get this at extreme velocities at
2700-2800 fps or more, which in our big bore rifles is somewhat extreme.......... Lead core
bullets will be effected in a serious manner at extreme velocities, followed by copper, and
then brass........ Nose Profile and Construction & Material are very important for Factor #6.........!!!

#7 Barrel Twist Rate

Barrel twist rate really only becomes a factor when Factor #1 is DEFICIENT....... If the meplat
of caliber is undersized, less than 65%, then faster twist rates WILL INCREASE the depth of
penetration by increasing the stability of terminal penetration. A 65% Meplat of Caliber can
stabilize in slower twist rates of 1:18, or even slower...... I have seen 65% Meplat of Caliber
stabilize with ZERO TWIST....... I have seen 50% Meplat of Caliber stability increase with
faster twist rates, and have documentation to prove it, several times...... If you are using a
properly designed Solid, then twist rate becomes less important, and more important if you
are not using a proper designed solid. Fast Twist Rates can also increase stability of even RN
Solids of decent design, hardly anything can increase stability of a more pointy RN FMJ....

#8 Sectional Density

Sectional Density will ONLY BE A FACTOR with two bullets that are exactly the same in every
other Factor or aspect. Factors #1 and #2 far outweigh Sectional Density in the terminal
performance of Solids. We can take a properly designed 458 caliber 325 gr Solid and far
out penetrate in depth and stability a poorly designed 550 gr 458 caliber bullet....... My son
recently shot a medium sized elephant at 10 yards, perfectly executed side brain shot, with a
350 gr .474 caliber properly designed solid at 2200 fps. This bullet exited the head on the
far side and still may be going for all I know. A 350 gr .474 caliber bullet has a sectional
density of .223, and I personally would choose this little 350 gr bullet over the Woodleigh
500 gr RN FMJ at .4725 (ones I have here) any and every day for any mission............

These are undeniable facts, and can be proven over and over and over again in all test work,
and these factors have been exercised in the field and have proven themselves in the field,
many many times over...... These are the 8 Factors of Terminal Penetration of Solid
Bullets.................

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MaxP said:

You are isolating the one instance where SD may matter, when all else (including material and hardness) is equal save for weight.

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MaxP said:

Still firmly believe that even with the right bullets the .44 is an underachiever. It will get it done no doubt, but in every instance I have seen them used on big game animals in the 1,400-lb. range, follow up shots fail to impress. While highly "unscientific," the bigger calibers (loaded correctly) just hit harder and tend to put the animal down in more dramatic fashion when good placement is employed.

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CraigC said:

How many times did you and Jack shoot that buffalo with your .500's in 2016? Sorry but I don't see a dramatic difference. We've seen Cape buffalo soak up numerous .577's without going down. This is what I mean by eliminating the "anecdotal nonsense". People are going to see what they want to see and everything is subject to interpretation. No two people are going to perceive the same occurrence the same way. Coupled with the fact that no two critters are going to react the same way. You'd have to kill 1000 buffalo with each load to determine anything meaningful. In the end, we all usually come out the same way we went in. Some believe bigger is better, some believe in velocity. Others are somewhere between.

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CraigC said:

If sectional density doesn't matter then weight doesn't matter. If weight doesn't matter, then the solid copper bullets should penetrate the same as those with a lead core, such as the Barnes Buster and Grizzly Punch. If weight doesn't matter then we should be able to use something even lighter than copper, as long as it has the right shape and doesn't deform. Is there evidence to support this theory? Other than vague extrapolations from a company that only sells solid copper bullets?

It's a very different argument to say that weight doesn't matter than it is to say that monolithic solids need less of it to work.

All of which I might add are not the topic of this thread. Does weight not matter with cast bullets either? I guess we can all switch to 200gr bullets for our buffalo hunting then. Cool!

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