Hi 416SW
If you read through the "Comparing The Big Bores" section of my website you will find all the comparrisons you are asking about both in .475 and .510 calibers. In .475 I loaded my 470 Mbogo to 2150 to represent the 470 Nitro Express and to 2500 fps with the same bullet. The 500 Jeffery load and the 505 Gibbs loads are with the same weight bullet at 2300 fps and 2400 fps. The 500 A-Square loads are loaded to 2150 to represent the 500 Nitro and to 2400 for the 500 A-Square. The difference between the nose shapes is also discussed ( for different round nose shapes eg. blunt Barnes Solid and Hornady round nose) with two loadings at the same velocity in my 470 Mbogo. I think you will find the site very informative.
Hi Alf,
I have Mike LaGrange's book and found it very interesting and I think it was key to me doing different tests but trying to build a better mouse trap at the same time. With the square tube test I tried to eliminate the friction to get a truer reading for the test results. With credit given to Mike. The plywood squares that he shot and pictured on page D of the color photo series look as though the bullets couldn't of had a travel path where the shots didn't interfere with one another in some cases. It also appeared that table 10 indicates that some bullets were soft points and some were solids for the square tube test. The other point is that his book is from 1990 and todays bullets both soft and solid are in a different ball park altogether. He did an awesome job of putting forward good information for people like ourselves with a common interest.

As to the bullets used they were all 560 Grain GS Custom solids. The original bullets discussed for the 45/70 were 550 grain hard cast bullets which are basically a solid. So the 560 solid in .475 should be a good representation with the different velocities.

The interesting result I though is when you take the highest penetration number for each velocity and compare the gains. The six hundred fps gain from 1550 to 2150 gains 16 inches of penetration and the 250 fps increase from 2150 to 2400 fps gains 6 inches of penetration. It makes me curious if a shot was taken at 250 fps less or 1900 fps would the difference in penetration be closer to 6 inches and if you increased the velocity by another 250 fps if the gain would be 6 inches of penetration or would you only realize 3 inches as Alf was suggesting.

This test is a comparrison with as many things being equal as possible and there probably is a direct correlation to penetration in game animals but I'm sure the end results will be the same. Shoot a 560 grain flat nose solid .475 bullet at 2400 fps and you better make sure everything is clear behind the target animal or you might be on a very quick two Buffalo Safari.
Take care,
Dave

Gday Dave
Your site looks good it's been a while since I looked at it.

What I meant was different bullet weights in the same caliber.

My question is, in say 50 cal will a 500grn at 2400fps penetrate more or less than a 600grn at 2300fps
The bullets need to be the same construction and front profile though, mono would be fine.

Hi 416SW,
Those results are basically there. If you go to page 6 the Square tube test loads which are the same for the plywood penetration test. The loads show the .510 caliber 600 grain bullet at 2150 fps compared to a 525 grain bullet at both 2300 and 2400 fps. It also shows the same 600 grain bullet at 2400 fps. All these bullets are the Barnes solids which have the same nose shape. It shows on page 7 that the 600 grain bullet for the 500 Nitro at 2150 fps penetrates deeper than the 525 load of the 505 Gibbs at 2300 fps and the same as the 525 grain load of the 500 Jeffery at 2400 fps. The .475 loads do only show the same bullet at different velocities when comparing the same bullet shape which in this case is the Barnes Solids. When are you guys going to give us back our summer.
Take good care,
Dave

.470Mbogo,

Thanks for the time and trouble. I can tell you one thing for sure. I have never had penetration problem with any 500gr projectile on any buffalo or anything else I've ever shot with my .458Lott. I load them at 2300 fps. Which is right in line with your findings. I've had full length wise penetration with an ass shot after the bullet (a solid) broke the buffs hip. And thats good enough for me.

I just can't believe that a .45-70 at 1500 fps would do that. In think the .45-70 as a large dangerous game rifle is pretty much a stupid human trick, though under the right circunstances it'll work just fine.

Now I have a friend who is a .45-70 nut who's shot 3 buffalo with his to good effect. God bless him. But we had a little contest on a mesquite tree in Texas after he informed me of the superior penetration qualities of his 500and whatever grain garret bumm ripper loads. In anycase his bullets did not go all the way through the tree and mine did. He immediatley claimed that it was the wood and that in a buffalo they would indeed outpenetrate my Lott. what does this prove? Only that we are completely safe from any mesquite trees that are apt to come totally uncorked in the near future. As Will said there is just no telling what a given bullet will do on a given day. It depends on a lot of things.

But the major reason that .45-70 all need to hang their hats on the low velocity therory is really quite simple. Their chosen cartridge is not capable of pushing a heavy bullet any faster. If it were they'd all be doing it. they have no choice but to shoot low velocity. And therefore try and prove to the worls that it the only way to go.

Thanks again Dave, I hadn't looked at all the other data on your site lately, forgot about the other tests, will review. Did see the pictures of my 470 Mbogo "working rifle" linked in now, along with Canuck's and yours.

It seems that the penetration of the GSC in plywood is proportional to something besides "momentum density" or "kinetic energy density" for the range of velocities you tested. The exponent on that curve varies somewhere between 0 and 2, and I don't even want to think about it!

Impact medium and bullet characteristcs are too complex for all inclusive formulae, though some might try a limited equation for a specific bullet in a specific medium.

For some specific enlightenment, I would just like to test flat nosed copper or brass .375 caliber bullets of

1) 265 to 270 grains at 2900 fps (about 5000 ft-lbs)

versus

2) 300 grains at 2750 fps (about 5000 ft-lbs)

If the two bullets of different weight and same nose cannot be found, it seems that grinding and polishing the base of a 300 grain bullet down to the lesser weight will remove the nose shape factor variation if done carefully to avoid screwing with bullet yaw/precession at exit from a good crown.

Can anybody predict which of 1) and 2) above would penetrate better in plywood or water? Differences may be small, or would one be decisively better than the other?

If anyone can predict that, then how will 3) compare in wood and water:

3) 350 grain Woodleigh .375 FMJ at 2550 fps (about 5000 ft-lbs)

This would delve into the high velocity end of things pretty well, and see how the "medium" bullets stack up on penetration against the 470 Mbogo.

I finally made it out to do penetration tests for the heavy for caliber bullets at different velocities. First the loads had to be made up and the low velocity loads were quite interesting to say the least. Using my 470 Mbogo and the heavy for caliber GS Custom 560 grain bullets with a sectional density of .354 I tried to find the correct powders and loads. H870 was too slow and messy so I ended up using H1000 which still left powder deposits in the barrel after each firing. The loads I settled on are as follows:

106 grains of H1000 560 GS Custom 1550 fps velocity
97 grains of RL15 560 GS Custom 2150 fps velocity
109 grains of RL15 560 GS Custom 2400 fps velocity

Two rounds at each velocity were fired into a test box made up of 11.5 by 11.5 3/4 plywood squares stacked tightly together like a loaf of bread. The total depth of the plywood squares was 60 inches. After the six shots were fired the plywood squares were pulled apart from the back of the box until a fired bullet was exposed. At this point the distance from the front of the box to the bullet tip was measured and recorded. All shots were fired at point blank range to make sure that each bullet would have it's own clear path of travel.
The test box:


The six fired shots:left shots 1550 fps, center 2150 fps and the right two shots were at 2400 fps


The penetration results were as follows:
The two bullets loaded to a velocity of 2400 fps penetrated 44 and 42.5 inches
The two bullets loaded to a velocity of 2150 fps penetrated
38 and 36.5 inches
The two bullets loaded to a velocity of 1550 fps penetrated 22 and 20 inches.
This photo shows the last 560 grain GS Custom bullet loaded at 1550 fps and shows the clear penetration path of the other 5 shots.

This clearly show that a heavy for caliber or a heavy bullet driven at a higher velocity will penetrate deeper than a bullet starting off with a lower velocity. A 45/70 with a 550 grain bullet starting off at 1500 fps will not out penetrate a 500 grain bullet starting off at 2350 fps or the 458 Lott velocity. The information and the video of the bullet recovery will be posted up on my site for future reference or for interest sake alone.
Take good care,
Dave

Interesting data, thank you for the effort. I have one question though. Is wood really an appropriate medium? I don't know about anybody else, but I don't hunt trees (although I've hit a few that got in the way). Ballistic gelatin would be a closer approximation of flesh. One can make the stuff, the recipe is on the web.

Quote : "A 45/70 with a 550 grain bullet starting off at 1500 fps will not out penetrate a 500 grain bullet starting off at 2350 fps or the 458 Lott velocity"


Now Dave!! Dont say things like that, the 45-70 Guide gun freaks are going to stop by and tell you how the lengthwised 18 feet of elephant spine after "someones" PH failed to stop it with a 458 Lott, only getting 12 inches of penetration.

Interesting.

Thanks for sharing.

I bet the results would be similar wether they are shot into gelatin, water, sheetrock or steel for that matter.

I have found that the faster they go the farther the penetration. Unless the velocity tears the bullet up but then you would be using the wrong kind of bullet.

Thanks Dave, I am still waiting for the muddy cow pasture to dry out enough and the crick to go down for me to drive down and dip 5 gallon buckets of muddy water. I may just go the plywood route first before laying the buckets end to end, ten in a row to see how many it takes to stop X bullet at x velocity versus Y bullet at y velocity. Maybe a piece of plywood between each bucket would add to the appropriateness of my medium.
Ballistic gelatin doesn't duplicate bone very well, and is more appropriate for handgun soft bullet loads.

Anyway, it is good to know that about 4 feet of 3/4" plywood sandwich would stop a bullet like the 470 Mbogo 560 grain FN solid.

Of course, the question will be asked, was the bullet gone to sleep and fully stabilized when hitting the boards just off the muzzle? Might the bullets have done better if they impacted the boards 25 yards down range, assuming the three different impact velocities of each was adjusted to be same as the velocities you tested?

Anyway, all three velocities were at equal disadvantage for this, and part of the advantage to the higher velocity is the faster spin from the same twist, besides just sheer momentum.

A tough enough bullet will penetrate this medium better with more speed. Couldn't say the same for frangible softs, of course.

But you stopped at the "magic" 2400 fps. How about 500 grain FN solid bullets at 2200, 2400, and 2600 fps from the 470 Mbogo?

I might be able to do that fine tuning of your test if you haven't.

Thanks Dave

How about a test with 2 buleets of the same manufacturer with the same frontal profile and construction but 100grn different in weight and say 150-200fps diff in vel, the heavier one going slower of course.
FMJ would be best maybe you could cut 100grns off to make a lighter one, but then you would also have to cut the heavier one so they were the same at the back ie. lead exposed and able to be squeezed out.

Dave- Congrats, you have finally proven unequevocably what we all have been saying for ages. Damn a 45/70 at 10fps just came through the earth at my feet and nearly got me. Somebody like PC in Australia musta fired it at me.
Ha Ha ha! I have also seen exactly the same results when testing heavy weight solids on oak logs. For those excited about Balistic gelatin, the results in my testing using that stuff were no better than the logs. Interestingly, I actually had more solids veer off and sometimes come out of the medium with slow bullets than with faster ones.
By the way I got the stock. Thank you very much. -Rob

416SW,
Thanks for that idea! I would suggest a monometal solid like the 560 grain 470 Mbogo bullet, just cut down at the base to go from 560 grains at 2400 fps down to 460 grains at 2700 fps. That would be informative.

Cutting the same bullet down to maintain the frontal profile for both weights is the critical item that has been troubling me about comparing .375 solids.

300 grains at 2400 and 2700 fps versus 270 grains at 2600 and 2900 fps for example.

We don't want any lead squirting out of any so stick to the monometals, eh?

And in this artificial medium of dry, hard boards, would the round nose work better than the flat nose, if only it would stay on course and penetrate as straight. So there is the rub. The flat nose should be most reliable in any situation.

In an aqueous medium, and the mixed medium of skin, muscle bone, viscera, and blood, the flat nose is supposed to be the best according to Norbert's superpenetrator testing.

It looks like Dave is getting no deformation of the GSC FN. I think GSC shot them into 55 gallon steel drums full of sand to get them to mushroom slightly.

Hi Ron,
There are always questions that can be asked and experinments or comparisons. But I think that this is a pretty good comparisons overall. Plywood is very consistent for comparrisons. I think that you would have a pretty tough time getting enough gelatin into a container to fire that 560 into at 2400 fps. As far as penetration in an animal this would represent end to end pass throughs with the 2400 fps velocity. I was impressed that the coating never came off of the bullets. I already did the bullet stabilization and the fact of the bullet going to sleep by loading bullets to an impact velocity of 2400 fps and uploading the loads for extended distances which would give the bullet a chance to go to sleep plus increase the rotation rate and all three bullets penetrated to the same depth. Personally I think the crown finish is the key to that issue. A perfect crown is a perfect exit. It would be interesting to take those five gallon snap lid containers full of water end to end to see what the penetration would be in an aqueaous state. With those jugs standing upright there are just too many opposing curves that might lead to deflection. If you made a V to lay the containers in end to end you should get maximum penetration. I might have to try that. If nothing else it would make one hell of a slpash. I'll have to wait for a sunny day though.
Take good care,
Dave

HI Ron,
I wanted to do this with the Bridger bullets but ran short of bulets while trying to get the load velocities. If you wanted to do the testing with the same shaped bullets just get John to make you some up. I have 540 and 500 Bridgers with the same shape and nose. It all breaks down to sectional density, the higher the number the better the penetration with the same shaped bullet. If you increase weight and sectional density you can load the heavier bullet to lower velocities and still have the same penetration as the faster lighter bullet. Keep the velocities the same and the heavier bullet goes deeper.
Take care,
Dave

I think it is a given that higher velocities generally give greater penetration, e.g., the Lott will out penetrate the 458 WM.



I fell that one of the true mysteries is the effect of the flat nose. Does it really penetrate more or does it just deflect less, and therefore penetrates deeper? Or is there really any effect at all?



Couple this with the bullet length to weight ratio. Long monometal bullets I do not believe will penetrate that well, in my experience (no methodical testing).



And to really mess things up, two seemingly identical shots on game can give widely disparate penetration results, on heavy game anyway.

RIP,
I think you've got it. When loading any caliber to maximum safe pressure, all things being the same on bullet profile and construction. Do we want to load a light bullet and go fast or a heavy bullet and go slower? Which theory gives better penetration? That is the real question IMO.
Ghost

Now Dave you have missed the magic formula and proven nothing.

The slow heavy bullets need to be flat nosed hard cast bullets and need to be fired from a cheap lever action with a tubular magazine.

Then you will see that amazing penetration.

Bill,
you quote:

>I think it is a given that higher velocities generally give greater penetration, e.g., the Lott will out penetrate the 458 WM.
--without any doubt. The only science based figure is the "momentum density", used also in military research.

>I fell that one of the true mysteries is the effect of the flat nose. Does it really penetrate more or does it just deflect less, and therefore penetrates deeper? Or is there really any effect at all?
--in your words, the flat nose deflects less, but only in aqueous media (tissue).In hard materials (plywood, bone) it penetrates less than a small round nose. The SuperPenetrator is an optimized compromise. We have to have in mind the two different mechanism of penetration in aqueous tissue or hard materials.

>Couple this with the bullet length to weight ratio. Long monometal bullets I do not believe will penetrate that well, in my experience (no methodical testing).
--Yes, because the spin for stabilisation in game must be higher for the same penetration length.

>And to really mess things up, two seemingly identical shots on game can give widely disparate penetration results, on heavy game anyway.
--Yes, because the sequences and relative amount of aqueous tissue and hard tissue (bone, sinew) are different from shot to shot.


grosswildjagd.de
My website may be out of order for a few days

.

Dave,

I am sorry for you . I know that you were hoping that these tests would disprove the laws of physics and make you a very famous man. As Norbert stated momentum density defines the penetration potential of a projectile. Point geometry is merely a fine tuning, in that is tweaks forces exerted upon the projectiles during flight to keep the projectile stable i.e. no tumbling, yawing off straight path, etc. Therefore, point geometry could have a significant effect on straight line penetration.

Momentum density it defined as the momentum of the projectile divided by the projectile's cross sectional area.

The momentum densities for Dave's test loads are (units are lbm/sec-in):
1550 fps - 57.41
2150 fps - 79.63
2400 fps - 88.89

A projectile will penetrate, as long as, the shear stress exerted by the projectile on the target is greater than the shear strength of the target. Shear stress is defined as the force of the projectile divided by the projectile's cross sectional area.

Now the reason momentum is of interest is this. Momentum is mass time velocity. Force is mass times acceleration. So if we integrate momentum with respect to time, ie the time rate change of momentum, we achieve the force curve! Armed with the force curve we can calculate, accurately I might add, the penetration of a projectile in the test media for which the force curve was generated (in Dave's case plywood). The military typically performs these tests for armor plate, masonry, and even earth structures.

So what did I say? I said what Dave's test said, which is what the laws of physics say. The laws of physics say simply, that for a given bullet diameter the faster it goes the deeper it penetrates!

Keep in mind, that with soft point bullets the bullet's actual diameter increases rapidly, due to bullet expansion. In other words, the momentum density of soft point bullets changes due to both decelleration and bullet plastic deformation with respect to time, while with a solid non-deforming bullet, the momentum density changes only due to bullet decceleration with respect to time. It may be easier to think of the expansion of a soft point bullet like a parachute opening, the soft point by design is supposed to slow down faster to dump it's energy at a greater rate into the target. Therefore, it is significantly more complicated to generate a penetration curve for a soft point, expanding bullet, than with the solid non-expanding bullet.

I think a more advanced, and therefore much more meaningful test, would be to test several different nose point geometries at different velocities to see what effect this variable plays in the penetration of plywood boards. Of course this costs money so I immediately understand if Dave doesn't want to go there.

Dave, I say "Myth Busted!!" . Damned good job. I hope you had fun bustin' that myth too.

Hope I didn't loose anyone with the technical mumbo jumbo.

Scott

Alf,

It really isn't that simple. I suspect the Weatherby's lack of performance has more to do with:

1.) Loss of bullet stability in flight through the target. The forces acting upon the bullet increase with speed and density of penetrating media. These increases can be HUGE!

2.) The bullets are deforming which is adversely effecting the momentum density, and contributing to number #1.

The previous points are strictly 'technically speaking' however.

From a real world perspective, I agree there is an 'optimum' operational velocity window for maximum penetration and/or tissue trauma (depending upon solid or soft point bullets). This 'window' is a function of bullet geometry and material/structure.

Scott

Awesome Dave,
and while it doesn't PROVE what these will do on game, it certainly benchmarks what they will DO...

of course, now someone will come along, say "oh, if you get charged by a wooden pony" or some other BS... Just laugh em off, offer to share load data, and have them shoot COWS or something, just to PROVE that the results aren't reversed.


and, for what it's worth, i've found reduced velocities will eventually not exit a great big ole mesquit tree...

jeffe

470, thanks for the informative posting.

Now the next question is:

Will Garrett put this on his website?

The 45-70 is a weak cape buffalo cartridge at best.

Great stuff Dave! I guess it doesn't matter that you spent a great deal of time and $$ proving what you already knew when you're having that much fun. Wish I was there!



It'll be nice when you get this stuff on your website. Everytime someone posts a link to Garrett's misinformation, I am sure someone will post one to yours!



I was thinkin' yesterday...it would have been nice to see if your 45/70 would have penetrated close to as far as the slowest 470 load you used. I bought a few 550gr Craters from JB Young...they would be just the ticket for comparison purposes. They shoot like a hot damn in my 45/70, so I've got an order in for a few more. If you want a few to try, I'd be happy to ship some down.



I noticed in your pic's that your scenery is a little different than ours. I haven't seen dirt or water for quite a while now. We are enjoying a chinook today though...+4degC! Its a tropical heat wave!



Got your message too. I was up at the ranch murdering one of Dad's buffalo. I used his crossbow and it worked like a charm. Looks like the hot-cheese smokies might have to wait a month or so though. I will give you a call this week and share the details.



Cheers,

Canuck

A critical point in this discussion has not been mentioned, as I am not personally familiar with the bullets used in this educational test. I suspect many other readers are likewise unfamiliar with the buulets used.

"Higher velocity equalling deeper penetration" ONLY applies to "solid" bullets, i.e.: bullets which do NOT deform in any way. Looking at the nose of that one peeking out of the plywood surely tells me that the GS Customs are indeed very "solid".

In the case of softpoints, greater speed usually causes greater expansion and/or bullet-weight loss, both of which will REDUCE penetration in many cases as the velocity goes up. It is perfectly possible that with SOME bullets, a .45-70 will penetrate deeper than a max-loaded .460 with the same bullets, simply due to the .460 causing more expansion or weight loss (meaning more frontal area, and hence reduced sectional density AFTER IMPACT, hence less penetration).

Solids and softnoses are very different critters, and their behaviors are markedly different as well. We have to make certain we're all talking about the same thing.

The nose-shape on solids makes an interesting topic, too. I've heard that the old 300-grain Winchester .375 solids, with their small flat-point, were disliked by many pros because of a tendency to veer off-course in the animals. All the Kynoch solids I've seen used a very slippery-looking tapered round-nose profile with long straight shanks which were reputed to hold the bullet on-line more reliably than a shorter shank would. However, it seems to me that the round-nose would deflect off heavy bone to some extent, where a sharper-edged nose would tend to "bite" better and keep going straight(er)??

A solid's purpose in life in strictly penetration, and any nose shape that increases the resistance to penetration (such as a big flat-point)would be working against the basic purpose, wouldn't it?

It all comes down to a balancing act, I reckon, where we try to build something that does the job as efficiently as possible, and trading off the various design elements.

Regards from BruceB (aka Bren Mk1)

Bren Mk1,

That's a good post.

BruceB,

Thank you for saying what I said in much easier to understand terms.

Scott