Flat Nose Bullets

[44MAG#1]

Help me out on this, please.
On a HARD CAST or JACKETED bullet how does the Meplat of a flat nose bullet operate as far as producing a wound channel both permanent and temporary? Does the Meplat really do much?
What are the mechanics of the process? KEEPING in MIND that I am talking about HARD CAST or Jacketed not a soft alloy that smears the edges of the Meplat (FN) easily.
I know that passing through bone of any size can alter the nose but i am talking about mainly muscle tissue.
Thanks in advance for your time.

[TurnipEaterDown]

Someone can detail this more, but in my understanding it comes down to: Fluid cavitation -- non laminar, or turbulent flow field dynamics.

The flat nose is inefficient in a sense of fluid dynamics / flow, so, there is cavitation created at the bullet nose.
This cavitation energy contributes to cavity disruption / damage. Thus wounding.

So, recognizing that cavitation creates an enhancement of damage, then design actions can be taken to gain efficiency in creating desirable wound characteristics via cavitation created by fluid flow characteristics that are not laminar (i.e. they are turbulent).

A good read on this phenomena is the Woodleigh manual section on their Hydrostatically stabilized solids.

[TurnipEaterDown]

Should have added: Large meplats and high velocity are effective at creating large permanent wounds.

I shot a deer once w/ a 475 Linebaugh Long driving a 400 gr LBT WFN at 1660 fps muzzle velocity. The deer was 12 feet away. During dressing, I measured (pocket card ruler) the entrance & exit hole diameter on the hide at approximately 1.5 inches, and the hole through the lung tissue at 2 inches.

[Rapier]

I have a 45-70 Mauser, it and a 444 Marlin rifle are terrors with a big flat point SWC style bullets. The Mauser does 2,700 with a 300 and is a devastating crusher on hogs. The Marlin with a 240 at 2,400 removes the contents of the chest cavity on a deer, just liquifies everything. Both impacts resemble a lightning strike more than a bullet impact.
The hydraulics are tremendous.
I shot 3 hogs in one day, three shots, DRT, no kicking. My 445 SM does about the same at 2,000. It appears to be the combination of bullet shape, weight and velocity, expanding internal fluid upon impact. The impact is quite serious, much worse tissue damage than a round nose that pushes tissue out of the way.
Shot a 550 pound hog with a 357 round nose, 7 times, nothing like a Ruger BH, empty, standing next to a wounded 550 pound hog, that stands up as you are reloading. I got a whole new understanding of not enough gun. True story, note 7 shots.

[Bazoo]

I don’t understand it, but I take the word for it by several folks. I think Skeeter Skelton wrote about shooting jack rabbits with a 32 or 38. Anyways, he had round most bullets and would hit them but they’ll run off and took several hits to bring them down. He switched to flat pointed bullets, with no other change, and it brought the varmints down straight away. The round nose bullets sorta slip right through, whereas the flat nosed pushes material with it as it goes, disrupting surrounding tissue and delivering more shock.

[M-Tecs]

Help me out on this, please.
On a HARD CAST of JACKETED bullet how does the Meplat of a flat nose bullet operate as far as producing a wound channel both permanent and temporary? Does the Meplat really do much?
What are the mechanics of the process? KEEPING in MIND that I am talking about HARD CAST or Jacketed not a soft alloy that smears the edges of the Meplat (FN) easily.
I know that passing through bone of any size can alter the nose but i am talking about mainly muscle tissue.
Thanks in advance for your time.

Jacketed only means the lead core has a jacket on it. Jacketed can be had in jacketed soft point (JSP), Jacketed Hollow Point (JHP) or full metal jacket (FMJ).

Point design has a significant effect on the wound characteristics as does velocity.

https://ultimatereloader.com/reloadi...bullet-basics/

https://concealednation.org/2020/03/...types-of-ammo/

https://www.luckygunner.com/ammopedi...exposed%20lead.

https://www.targetbarn.com/broad-sid...point-bullets/

[44MAG#1]

Jacketed only means the lead core has a jacket on it. Jacketed can be had in jacketed soft point (JSP), Jacketed Hollow Point (JHP) or full metal jacket (FMJ).

Point design has a significant effect on the wound characteristics.

https://concealednation.org/2020/03/...types-of-ammo/

https://www.luckygunner.com/ammopedi...exposed%20lead.

https://www.targetbarn.com/broad-sid...point-bullets/

I corrected my mistake. I meant a HARD CAST or Jacketed Flat Point bullet that is NON DEFORMING meaning non expanding.

[M-Tecs]

I corrected my mistake. I meant a HARD CAST or Jacketed Flat Point bullet that is NON DEFORMING meaning non expanding.

That would be a solid or FMJ. Terminology does matter.

[44MAG#1]

That would be a solid or FMJ.

Yes I know that. I have a 458 Win Mag in both a Ruger #1 and An Encore handgun.
I have shot "Solids" in both.

[M-Tecs]

The fluted bullet designs do seem to work as claimed giving credence to point shape matters.

https://gunsmagazine.com/ammo/fluted...eat-or-gimmik/

https://www.glocktalk.com/threads/un...%20torn%20open.

[M-Tecs]

[44MAG#1]

I've seen two or three of those videos. I have some of that type of ammo for the 45 Auto. Never shot any of it.
BTW it is Underwood ammo.

[TurnipEaterDown]

One thing not mentioned here, but meaningful in that in relation to wounding capacity it also matters what happens After the bullet has proceeded some distance and nose shape changes (on an expanding projectile) and/or rotational velocity slows, is what happens to bullet stability.

I was on a trip years ago with a friend and he shot a boar (hog) of ~220 lbs broadside with a 285 gr HP in a 44 Contender. I can't state for an absolute fact, but since I provided the data for him to load with, I believe it was loaded at 1.73" w/ 24 gr W296. No slouch load, these did ~1350 fps out of a 7.5" SBH of mine.
The bullet had a brass jacket and a large HP. The promotional concept was rapid opening, and after some distance traveled in the body the HP would shear off leaving a sort of non-expanding wad cutter plug of ~ 190 gr to travel on.
So, again, he took a broadside shot, probably 50 yds, into ribcage. Somehow I most usually get the field dressing and rough butchering job, probably because I enjoy investigating what happens after the shot, and my friends do other things for me in life and I feel a little sense of payback is required. So, also having been the one prompting the purchase of these components, I went on the 'where did the bullet go' search. The bullet entered the ribcage, expanded, ran up against something internal that was resilient (I think it was diaphragm or heart tissue, then Turned, went up to the spinal column between two ribs, turned again, and tunneled along the outside of the vertebrae until it stopped 1/2 way up the neck.
Yep, it was that "desirable" ~190 gr sort-of-WC shape when it stopped. Good performance? I'd say: No.

There was an article I read related to this somewhere around that time, think it was the A-Square manual, and it has to do with conservation of momentum, overturning moment, resilient (stretchy) tissue, and nose form (that's where I want to make this point, as the discussion was on nose form originally and wounding capacity).
Round noses, and "mushroomed" expanding cup & core, will be subject to not following a straight path through a target body. The problem with the expanded round nose (the worst offender) is that it can get steered by the resilient members in the target body as it loses speed and expands diameter creating opportunity for increased overturning moment, and lowered rotational speed due to conservation of momentum. It can not gain rotational energy after leaving the barrel, so as it spins slower inside teh body after expansion, it becomes less stable.
Short round noses are particularly subject to this, especially when shot at low speed with low spin rate (slow twists, low velocity) and I also remember reading that this is basically what hampers the 45 ACP Ball load in lethality. The RN form is great for feeding into chamber, but is at a disadvantage for wounding (poor fluid disruption / cavitation capability, and easily overturned). It somewhat begs for a better nose form, and HPs are somewhat counterproductive. The HP can increase the overturning moment applied, and will reduce the spin rate after expansion because of conservation of momentum, thus leading to a loss of stability.
I have been intrigued by these fluted copper projectiles for the older ACP family cartridges and their cousins, as it seems like possible useful improvement in regards to terminal ballistics.

[44MAG#1]

One thing not mentioned here, but meaningful in that in relation to wounding capacity it also matters what happens After the bullet has proceeded some distance and nose shape changes (on an expanding projectile) and/or rotational velocity slows, is what happens to bullet stability.

I was on a trip years ago with a friend and he shot a boar (hog) of ~220 lbs broadside with a 285 gr HP in a 44 Contender. I can't state for an absolute fact, but since I provided the data for him to load with, I believe it was loaded at 1.73" w/ 24 gr W296. No slouch load, these did ~1350 fps out of a 7.5" SBH of mine.
The bullet had a brass jacket and a large HP. The promotional concept was rapid opening, and after some distance traveled in the body the HP would shear off leaving a sort of non-expanding wad cutter plug of ~ 190 gr to travel on.
So, again, he took a broadside shot, probably 50 yds, into ribcage. Somehow I most usually get the field dressing and rough butchering job, probably because I enjoy investigating what happens after the shot, and my friends do other things for me in life and I feel a little sense of payback is required. So, also having been the one prompting the purchase of these components, I went on the 'where did the bullet go' search. The bullet entered the ribcage, expanded, ran up against something internal that was resilient (I think it was diaphragm or heart tissue, then Turned, went up to the spinal column between two ribs, turned again, and tunneled along the outside of the vertebrae until it stopped 1/2 way up the neck.
Yep, it was that "desirable" ~190 gr sort-of-WC shape when it stopped. Good performance? I'd say: No.

There was an article I read related to this somewhere around that time, think it was the A-Square manual, and it has to do with conservation of momentum, overturning moment, resilient (stretchy) tissue, and nose form (that's where I want to make this point, as the discussion was on nose form originally and wounding capacity).
Round noses, and "mushroomed" expanding cup & core, will be subject to not following a straight path through a target body. The problem with the expanded round nose (the worst offender) is that it can get steered by the resilient members in the target body as it loses speed and expands diameter creating opportunity for increased overturning moment, and lowered rotational speed due to conservation of momentum. It can not gain rotational energy after leaving the barrel, so as it spins slower inside teh body after expansion, it becomes less stable.
Short round noses are particularly subject to this, especially when shot at low speed with low spin rate (slow twists, low velocity) and I also remember reading that this is basically what hampers the 45 ACP Ball load in lethality. The RN form is great for feeding into chamber, but is at a disadvantage for wounding (poor fluid disruption / cavitation capability, and easily overturned). It somewhat begs for a better nose form, and HPs are somewhat counterproductive. The HP can increase the overturning moment applied, and will reduce the spin rate after expansion because of conservation of momentum, thus leading to a loss of stability.
I have been intrigued by these fluted copper projectiles for the older ACP family cartridges and their cousins, as it seems like possible useful improvement in regards to terminal ballistics.

While that is interesting I am interested in FLAT POINT NON DEFORMING BULLETS either hard cast or Jacketed Flat Nose.

[cainttype]

While that is interesting I am interested in FLAT POINT NON DEFORMING BULLETS either hard cast or Jacketed Flat Nose.

From Veral Smith discussing “Displacement Velocity” and simple calculations to describe the autopsy results of wound paths in various game animals… 02/05/2005

“First understand that it is NOT a theory. I would have let you call it a concept 15 years ago, but it is now a fact, proven over and over by thousands, and no one who has tried it has questioned it's accuracy since I published it in 1990.

The easy calculation is meplat diameter in thousandths of an inch X Velocity divided by 4.

Ignore the range you'll expect to be shooting at. Just calculate it off muzzle velocity and it will be close out to as far as most can hit with a revolver or rifles which thrive on 'Pumpkin ball' type bullets.

Get the DV up to 80 minimum, for quick kills on deer and larger game, best with 100 to 125. Don't go over that very much or kill speed will go down.

If using a small caliber gun which doesn't have the omph to get the 80 minimum desired DV, you'll get good clean kills at DV's down to 60 if the bullets are placed into good vital areas of the chest. i.e. If they cut major blood vessels, heart, or the thicker parts of the lungs.

Expect approximate wound diameters straight through the muscle and organ parts of game as follows:

60 to 70 DV 1/2 inch diameter
75 to 90 DV 3/4 inch +
100 DV 1 inch +
125 DV 1 1/4 inch +
If wound diameter goes up to 1 3/8 inch or greater kill speed drops off rapidly, which means game runs quite a way before expiring. With a DV of 100 to 125, game up to elk moose and bison almost always fold in their tracks or take a few steps at most.

Veral Smith”

[jcren]

Think snow plow hitting a pile of wet slush at speed vs a v-hull boat cutting through the water. Also how old timers would cut the point off a nail being driven into oak or other hard, split prone lumber. Crush and splash instead of neadling through.

[TurnipEaterDown]

One of the reasons I offered what I did in post #13 was the comments on stability.

The bullet which shed its nose in my posted experience was no longer expanding, it basically was a solid w/ a slightly rounded WC shape, and this did not perform well in terms of predictable bullet path.
While the start velocity in that form (having just shed the nose) is not definable, and neither is its spin rate, it is undeniable that it was less than muzzle velocity of the entire projectile and less than muzzle spin rate, and yet still sufficient to penetrate some 12"+ of muscle tissue in the boar. Under these conditions, this bullet did not follow a useful path. It was turned by and away from vital internal members.
The same would be expected to happen with a non deforming bullet if it started under conditions similar to what that bullet experienced after shedding the nose.

Stability should be considered along with wounding capability. If unstable, idealized wounding capability may not be realized.

[cainttype]

For a more detailed scientific treatise on Veral’s conclusions/theory, along with the OP’s request, try; https://www.rathcoombe.net/sci-tech/...s/methods.html

[TurnipEaterDown]

You have my thanks for post #18. I will try to take the time to read through the whole thing, looks quite in depth.

[Daekar]

From Veral Smith discussing “Displacement Velocity” and simple calculations to describe the autopsy results of wound paths in various game animals… 02/05/2005

“First understand that it is NOT a theory. I would have let you call it a concept 15 years ago, but it is now a fact, proven over and over by thousands, and no one who has tried it has questioned it's accuracy since I published it in 1990.

The easy calculation is meplat diameter in thousandths of an inch X Velocity divided by 4.

Ignore the range you'll expect to be shooting at. Just calculate it off muzzle velocity and it will be close out to as far as most can hit with a revolver or rifles which thrive on 'Pumpkin ball' type bullets.

Get the DV up to 80 minimum, for quick kills on deer and larger game, best with 100 to 125. Don't go over that very much or kill speed will go down.

If using a small caliber gun which doesn't have the omph to get the 80 minimum desired DV, you'll get good clean kills at DV's down to 60 if the bullets are placed into good vital areas of the chest. i.e. If they cut major blood vessels, heart, or the thicker parts of the lungs.

Expect approximate wound diameters straight through the muscle and organ parts of game as follows:

60 to 70 DV 1/2 inch diameter
75 to 90 DV 3/4 inch +
100 DV 1 inch +
125 DV 1 1/4 inch +
If wound diameter goes up to 1 3/8 inch or greater kill speed drops off rapidly, which means game runs quite a way before expiring. With a DV of 100 to 125, game up to elk moose and bison almost always fold in their tracks or take a few steps at most.

Veral Smith”

That is very, very interesting, and is a model I haven't seen before. I haven't had a chance to delve into it deeply, but it tracks with intuition. My pet defensive boolit, the Accurate 36-159S, has a 0.300" meplat and I like to shoot it around 800fps. The formula says that comes out to DV=60, which feels about right. Push the same boolit to 1400fps in a full power 357mag, and you get 105, at the lower end of the recommended range for deer and larger game.

Of course, the model doesn't account for bullet weight and the associated penetration so it's not a complete picture, but it seems very handy for getting an idea of what speed you want to achieve for any given meplat size, and then vary the weight of the design you choose based on your penetration needs. Sounds like an ideal calculation to pair with VIRGEL.