Lehigh Bullet Flutes vs No Flutes

[Navin Johnson]

In a perfect world, the round nose bullet (FMJRN) would produce slightly greater damage than the flat nose bullet (FMJFM).

FMJFNs create larger stagnation pressure fields ahead of the bullet's nose than FMJRNs. The FMJFN's larger stagnation pressure field ejects soft tissue radially away from its path more forcefully than would an FMJRN. The increased radial displacement of the soft tissue moves the boundary flow separation point farther forward towards the nose of the bullet so less soft tissue makes direct contact with only a small portion of the bullet's leading surface area producing a narrow permanent cavity.

In stable, nose-forward flight, a very slight edge goes to the FMJRN. Because FMJRNs produce smaller stagnation pressure fields than FMJFNs, the boundary flow separation point moves to a point farther back along the FMJRN's length towards the base of the bullet. This allows more soft tissue to make direct contact with, and to be crushed by, the FMJRN's slightly larger leading (presented) surface area and produces a slightly wider permanent cavity. On a ''per unit of distance traveled'', a FMJRN in stable, nose-forward flight produces slightly more soft tissue damage than an FMJFN.

The small difference between the two configurations is unlikely to matter in human bodies because soft tissues surrounding the path of the bullet tend to embolize (a fancy $25-word meaning ''to swell and obstruct'') and restrict—or even completely stop—blood loss.

Thanks I thought I had read that before somewhere

Many seem to think the FMJFN Does way more damage than a FMJRN. Possibly confusing it with a true full wad cutter or semi wadcutter with a large meplat.

[the Schwartz]

Thanks I thought I had read that before somewhere

Many seem to think the FMJFN Does way more damage than a FMJRN. Possibly confusing it with a true full wad cutter or semi wadcutter with a large meplat.

Yep!

Until the Lehigh/Wilson Combat Extreme Defense ammunition is proven to be a superior option in research that includes its performance in shootings with LE agencies, it is nothing more than really expensive ball ammo.

[spyderco monkey]

Not surprisingly, Wilson Combat and Lehigh Defense go as far as to ''double down'' (in the YouTube video's description) with the same old worn-out marketing ploy that claims ''energy dump'' to be some sort of wounding mechanism.

Its my understanding that the screwdriver shape + flutes are intended to convert the temporary stretch cavity into tearing.

To my eye, the XD is basically a modernized version of the THV bullet:

https://www.quarryhs.co.uk/THV.htm



The THV concept was that the 'scoop' profile would transfer energy outwards and away from the projectile, in the hopes that this radical outward energy focus from the bullets shape would induce tearing.

We now know that the THV and other pistol bullets in the 300-400 ftlbs energy range dont have the energy to create tearing via temporary cavity alone.

The XD in theory may be able to succeed where the THV failed due to screwdriver shape. The screwdriver tip cuts a + into the target, and then the flutes channel the bullets energy outwards and into those cuts, potentially tearing those cuts wider. Whereas 300-400ftlbs may not be able to tear on its own, it may be enough to tear an existing cut, as tearing an existing cut requires less energy.

If the XD starts off with a 7mm across + cut, it and then the flutes are able to tear the + 3mm deeper on each side, then it could result in a 11mm/.43" across + cut.

I say in theory, as I have never tested the XD or shot one, and I have no stake in their success (and I carry JHP for my own defense) But the underlying theory of the XD seems more plausible to me then previous attempts like the THV or rival bullet designs like the ARX, which lack a cutting mechanism like the + tip of the XD.

I'd be curious to see how the XD performed in hunting, and whether the + cut hypothesis occurs, or if it just performs like ball.

[the Schwartz]

Its my understanding that the screwdriver shape + flutes are intended to convert the temporary stretch cavity into tearing.

To my eye, the XD is basically a modernized version of the THV bullet:

https://www.quarryhs.co.uk/THV.htm



The THV concept was that the 'scoop' profile would transfer energy outwards and away from the projectile, in the hopes that this radical outward energy focus from the bullets shape would induce tearing.

We now know that the THV and other pistol bullets in the 300-400 ftlbs energy range dont have the energy to create tearing via temporary cavity alone.

The XD in theory may be able to succeed where the THV failed due to screwdriver shape. The screwdriver tip cuts a + into the target, and then the flutes channel the bullets energy outwards and into those cuts, potentially tearing those cuts wider. Whereas 300-400ftlbs may not be able to tear on its own, it may be enough to tear an existing cut, as tearing an existing cut requires less energy.

If the XD starts off with a 7mm across + cut, it and then the flutes are able to tear the + 3mm deeper on each side, then it could result in a 11mm/.43" across + cut.

I say in theory, as I have never tested the XD or shot one, and I have no stake in their success (and I carry JHP for my own defense) But the underlying theory of the XD seems more plausible to me then previous attempts like the THV or rival bullet designs like the ARX, which lack a cutting mechanism like the + tip of the XD.

I'd be curious to see how the XD performed in hunting, and whether the + cut hypothesis occurs, or if it just performs like ball.

When it comes to this particular topic which has been revisited several times in this forum, I'll defer to Dr. Roberts' opinion as it relates to bullets with fluted noses since he has extensive experience with that design―

This idea of a solid projectile with flat point and flutes has been around for a long time. We tested a .45 Auto 185 gr +P solid w/flat point and flutes for NSW back in the late 1980's or so.

Despite media and vendor hype to the contrary, these solid fluted bullets just punch a hole in tissue like any FMJ--there is no mystical hydraulic energy, magical pressure spikes, absurdly enlarged wound cavity, etc...

Nonetheless, this design can be a good projectile and offer decent terminal performance.

The general design concept seems to have originated with Charles Kelsey and Devel in the early 1990s―

https://patents.google.com/patent/US5133261A/en

―and yet, after several iterations of the design over a span of three decades, it has languished in disuse (amongst military and law enforcement agencies) despite several manufacturers' repeated attempts to resurrect it in the marketplace. There is probably a reason for that.

It would seem that I am not alone in my regard for the design seeing it has nothing more than very expensive ball ammo.

ETA: It is worth continuing to bear in mind that tearing observed in a gelatin block as a result of a bullet passing through it does not necessarily correspond to what might occur when the same bullet passes through human soft tissues.

[spyderco monkey]

When it comes to this particular topic which has been revisited several times in this forum, I'll defer to Dr. Roberts' opinion as it relates to bullets with fluted noses since he has extensive experience with that design―



The general design concept seems to have originated with Charles Kelsey and Devel in the early 1990s―

https://patents.google.com/patent/US5133261A/en

―and yet, after several iterations of the design over a span of three decades, it has languished in disuse (amongst military and law enforcement agencies) despite several manufacturers' repeated attempts to resurrect it in the marketplace. There is probably a reason for that.

It would seem that I am not alone in my regard for the design seeing it has nothing more than very expensive ball ammo.

ETA: It is worth continuing to bear in mind that tearing observed in a gelatin block as a result of a bullet passing through it does not necessarily correspond to what might occur when the same bullet passes through human soft tissues.

Ah Devel, thank you, I've been trying to recall the original version. I had seen it maybe 2006-08 in one of the old school gun blogs, now defunct. The Gun Writer? They had a ton of great info on the 1986 Miami Shootout, and also a bunch of Miami Vice segements? It was a classic of the early guninternet.



I'm still quite curious to see how they would perform in hunting / hog elimination. That could show whether the + cut flute tearing hypothesis actually works in flesh, or if its simply a parlor trick to manipulate the properties of ballistics gel.

The absence of LEO use I dont consider definitive. The projectiles, both then and now, are substantially more expensive than JHP. Unloaded .355" XD projectiles were selling for about $.33 per projectile back when (2018-19) loaded HST could be had for $.40.

Nor has the projectile been offered by any of the ammo 'majors' who would be competitive for LEO/Mil contracts.

And of course the general 'lack of data leads to lack of data' dilemma.

No one is carrying them because theres no data to show it works so theres no data showing it works to encourage agencies to carry the ammo and generate data on its effectiveness.

Short of Lehigh sponsoring some LEO agency in a high crime area with free XD ammo, I'm not sure how that data log jam would be breached.

Hunting is likely the closest we can get to meat data.

[5pins]

Ah Devel, thank you, I've been trying to recall the original version. I had seen it maybe 2006-08 in one of the old school gun blogs, now defunct. The Gun Writer? They had a ton of great info on the 1986 Miami Shootout, and also a bunch of Miami Vice segements? It was a classic of the early guninternet.



I'm still quite curious to see how they would perform in hunting / hog elimination. That could show whether the + cut flute tearing hypothesis actually works in flesh, or if its simply a parlor trick to manipulate the properties of ballistics gel.

The absence of LEO use I dont consider definitive. The projectiles, both then and now, are substantially more expensive than JHP. Unloaded .355" XD projectiles were selling for about $.33 per projectile back when (2018-19) loaded HST could be had for $.40.

Nor has the projectile been offered by any of the ammo 'majors' who would be competitive for LEO/Mil contracts.

And of course the general 'lack of data leads to lack of data' dilemma.

No one is carrying them because theres no data to show it works so theres no data showing it works to encourage agencies to carry the ammo and generate data on its effectiveness.

Short of Lehigh sponsoring some LEO agency in a high crime area with free XD ammo, I'm not sure how that data log jam would be breached.

Hunting is likely the closest we can get to meat data.

The problem with hunting is it's anecdotal and subjective to interpretation by the person using it. Unless you could conduct testing in a controlled way, shooting several under the same conditions, there is no way of comparing the outcome.

[5pins]

At around the 2 minute mark in the video, he talks about "energy dump".

From the IWBA Wound Ballistics Review 1996 Vol 2 Num 3. page 42 WOUND BALLISTICS MISCONCEPTIONS by Duncan M acPherson

The belief that kinetic energy deposit in tissue is a fundamental wounding mechanism is very common and this assertion has been made by innumerable writers, most of whom have little or no understanding of either the physics or physiology involved. The popularity of this claim led me to devote an entire chapter in Bullet Penetration - Modeling the Dynamics and the Incapacitation Resulting from Wound Trauma to explaining energy relationships and why there is no general direct relationship between energy and the trauma that leads to incapacitation. No attempt is made to cover all this material here, but the following paragraph briefly summarizes the "bottom line" .

Attempts to determine bullet effectiveness or assign wound trauma incapacitation by assessing bullet kinetic energy are doomed to failure for two interconnected reasons: 1) damage is done by stress (force), not energy. 2) an indeterminate, but usually large, amount of the bullet kinetic energy leads to tissue stresses that are not large enough to cause significant trauma (especially in handgun loads).

https://generalcartridge.files.wordp...96-vol2no3.pdf

[TiroFijo]

Back when I lived in south africa in the early '90s, the THV bullets (made of bronze, don't know if they were originals or clones) were available for reloading and many people experimented with them, including the police. This was a time when a lot of defensive shooting in the real world was happening.

The faded into oblivion in a few years...

[the Schwartz]

The problem with hunting is it's anecdotal and subjective to interpretation by the person using it. Unless you could conduct testing in a controlled way, shooting several under the same conditions, there is no way of comparing the outcome.

Strasbourg Goat Tests anyone? /humor

[WDR]

The main appeal to me for an all copper solid bullet in a service or revolver caliber is deep penetration. The nose shapes may help or hinder that goal. Straight penetration and sharp frontal edges would be nice, for something like animal defense. I'm not really sure what copper offers over hard(er) cast lead, performance wise. So far, the juice isn't worth the squeeze for me to try all copper bullets in 9mm/.38/.357 loads.