Underwood 135 gr

[Raggedyman]

I posted a link near the top of this page which points to a lot of information on this very subject from folks whose job it is to analyze and predict projectile wounding. The "magic number" referred to by the FTU's paper, Dr. Roberts, and other experts is 2,000 fps. As mentioned, there are a lot of factors involved but typical handgun bullets, including the 10mm do not reach the threshold required to make TSC a significant wounding mechanism.

sqlbullet, I tested Underwood's 155 gr Gold Dot and it demonstrated insufficient penetration.

[REDLINE]

The number isn't "magic".  It's relevant, and empirical.

I realize that's been said already.  And therefore within the context of the conversation it's possible the 2200-2300 fps range is based on, concerned with, or verifiable by observation or experience rather than theory or pure logic.  I'm not arguing that at this point as I already threw out my thoughts in other posts below.  I was simply looking for any reference material stating the same.  It would seem the 2200-2300 fps was made up as general example to make a point.  Cool.  I don't agree with it, but I would have thought you could have just said that to begin with.

Supersonic velocity...hydrostatic shock...

I've never bought into a sound wave(s) from a projectile up to the highest speeds high powered rifle rounds like the Weatherby line of cartridges are capable, themselves producing wound damage beyond the permanent cavity.  A sound wave simply doesn't do that in and of itself.

A pressure wave, yes.  Not a sound wave.  I'm not saying super sonic sound waves don't do damage to tissue, as it's proven they can.  But it's more on a cellular level at best, if at all, in the time frame common projectiles like the ones were're generally refering to, take to penetrate while still at super sonic velocity.  We're talking about something that at best causes cell damage, but does not even cause additional bleeding from a peramanent or temporary stretch cavity where tearing did occur.  It's a pressure wave from the projectile, supersonic or not, that causes damage (tearing/overstretching of flesh to the extent of additional bleeding) beyond the permanent cavity.  Not a sonic effect.

Hydrostatic shock is simply poor terminology for pressure waves doing what they do.  Not the worst terminology in general, but not correct either.

It's not about whether a projectile is supersonic or not in regards to pressure waves.  All common projectiles down to the diminutive 25 Auto produce a pressure wave when going through flesh, supersonic or not.  The 25 Auto simply doesn't produce a kinetic energy level with enough force to damage tissues beyond their elastic limits, and therefore isn't capable of any damage outside the direct path of the projectile. 

Move on to the common handgun cartridges at higher velocity ranges (~1350 fps and up) carrying greater levels of kinetic energy (~500 ft-lbs and up) using hollow point bullets (because they transfer more available energy than non expanding bullets) and we do begin to see varying levels of additional damage (even if still minor compared to most rifle rounds) outside the permanent cavity. 

Add more velocity and energy with bullets that trasfer energy well compared to nonexpanding designs and the damage is enhanced further.  And further and further yet as more of what's required to build on the force that damages tissue outside the permanent cavity is added to the equation.  And eventually you get to such catastrophic level, like with some 257 Weatherby Magnum loads on a normal vitals broadside shot on Whitetail deer, and the whole front half of the animal may have to be discarded. 

Hence why some hunters prefer not to go beyond the level of power offered by the 30-30.  Sure, a 30-30 produces blood shot meat, just a lot less of it compared to higher powered rifles yet, and it still allows the use of something higher powered than most handgun rounds out of a rifle platform with a little better tradjectory than handgun rounds from rifle/carbine platforms.

You're absolutely correct when you say there is no magic number, especially when considering it's not just about velocity when considering projectile wounding.  But to suggest any wounding outside the permanent projectile path is nonexistent to any meaningful level till 2200-2300 fps is reached is simply not true.   Nor does it directly have to do with what's at supersonic velocity for any amount of penetration depth for tissue damage outside of the permanent projectile cavity to occur. 

[REDLINE]

I posted a link near the top of this page which points to a lot of information on this very subject from folks whose job it is to analyze and predict projectile wounding. The "magic number" referred to by the FTU's paper, Dr. Roberts, and other experts is 2,000 fps. As mentioned, there are a lot of factors involved but typical handgun bullets, including the 10mm do not reach the threshold required to make TSC a significant wounding mechanism.

This - http://www.firearmstactical.com/wound.htm - is the link you're refering to?

I missed it.  Could you point me to where it mentioned 2000 fps?  Maybe in a link within the links?

AFAIK the only time anyone in the IWBA every mentioned anything about 2000 fps was where they pointed out that the 2000 fps velocity was required for bullet fragments to create their own meaningful wound tracks outside of the main permanent crush cavity.  If you could show me anything else they've mentioned regarding the 2000 fps mark in regard to wounding I would love to get a look at it.   

[uz2bUSMC]

I posted a link near the top of this page which points to a lot of information on this very subject from folks whose job it is to analyze and predict projectile wounding. The "magic number" referred to by the FTU's paper, Dr. Roberts, and other experts is 2,000 fps. As mentioned, there are a lot of factors involved but typical handgun bullets, including the 10mm do not reach the threshold required to make TSC a significant wounding mechanism.

sqlbullet, I tested Underwood's 155 gr Gold Dot and it demonstrated insufficient penetration.

Do you know what they claim happens at 2000fps? It specifically says that the temp cavity can cause tissues that were weakened by fragmentation to tear at that velocity. That is what they say, not that it is sufficient enough at that point to overcome the elasticity of the tissue.

[uz2bUSMC]

Velocity alone is not the decideing factor here. That's why you have through and throughs without much damage with rifles such as the Dr mentioned in that video. But why is that? The bullet was traveling above the "magic number"? That's because bullet construction and the rate of transfer of energy is what is mostly important. The hydrdynamic pressure must be great enough to damage tissues not directly in the path of the bullet. According to others outside of the Fackler camp, handgun bullets can have damaging effects outside of the direct path of the bullet. They have to have a fair bit of energy and they have to transfer their energy more quickly than rifles. Rifles have it easier since they posses more energy and velocity but that does not mean that it does not happen with handguns. There is no magic threshold, it is linear. Sorry, but Fackler et al have not proven that this does not happen with handgun projectiles.

[4949shooter]

How are you, Miguel?

Long time no talk!

[sqlbullet]

I was out yesterday....But it has been covered I think.  Yes, I watched the video.

Redline, I think we are all on the same page.  It just sounds to me like you are saying this...."There is a range over which velicity/secondary wounding becomes significant".  But it also sounds like you are saying that such wounding can be a significant contributor to thread stoppage in 10mm, 357 magnum, etc.  And I don't agree with that.

[uz2bUSMC]

How are you, Miguel?

Long time no talk!

Hey Buddy, doin' good on my end. Hope all is well your way! Hit me up via PM when you get a chance, we'll catch up a bit.

[REDLINE]

I was out yesterday....But it has been covered I think.  Yes, I watched the video.

Redline, I think we are all on the same page.  It just sounds to me like you are saying this...."There is a range over which velicity/secondary wounding becomes significant".  But it also sounds like you are saying that such wounding can be a significant contributor to thread stoppage in 10mm, 357 magnum, etc.  And I don't agree with that.

I'm happy agreeing to disagree where our thoughts vary.  I think we all brought forward some good food-for-thought. 

[ak585479]

I posted a link near the top of this page which points to a lot of information on this very subject from folks whose job it is to analyze and predict projectile wounding. The "magic number" referred to by the FTU's paper, Dr. Roberts, and other experts is 2,000 fps. As mentioned, there are a lot of factors involved but typical handgun bullets, including the 10mm do not reach the threshold required to make TSC a significant wounding mechanism.

Sorry to bump an old thread but I just got my first 10mm (Glock 20 gen 3) and just joined the forums after this thread caught my eye since I just ordered some Underwood 135 gr JHP's.  So I understand they don't have the velocity to make the temporary cavity significant since they don't reach 2000fps (1580 avg chrono I've read).  Let me ask you guys this... my Glock 20 can fire 9x25 Dillon with just a conversion barrel.  Double Tap makes a 90 grain 9x25 Dillon that advertises 2100fps out of the muzzle.  Assuming it does that, Since that's higher than "the magic number" would that round make the TC significant?  Or are there other factors at work? Yes i know its not a 10mm but it is fired from a 10mm platform and its a 10mm casing  Thanks.

[The_Shadow]

The DT 9x25's were based on 6" test.  The shorter barrels don't yield the upper velocity for the 9x25's, commercial loadings are expensive for the most part.
The TC is usually shallow with bullets of this style, the projectiles like the 90 grain 0.355" dia. were made for performance from pistols like the 380ACP's.  Therefore I would think these in JHP would likely have total expansion on or slightly after impact.

Also these shorter lighter 0.355' projectiles seem to have poorer accuracy at distance.

There are some who have pushed the 135 gr 0.400" projectiles to 1700-1800 fps from the 10mm platforms with 4.75"-5" barrels.  This is pushing the envelope of the brass based on chamber case support and actually some have blown out the primers.

[ak585479]

The DT 9x25's were based on 6" test.  The shorter barrels don't yield the upper velocity fosr the 9x25's, commercial loadings are expensive for the most part.
The TC is usually shallow with bullets of this style, the projectiles like the 90 grain 0.355" dia. were made for performance from pistols like the 380ACP's.  Therefore I would think these in JHP would likely have total expansion on or slightly after impact.

Also these shorter lighter 0.355' projectiles seem to have poorer accuracy at distance.

There are some who have pushed the 135 gr 0.400" projectiles to 1700-1800 fps from the 10mm platforms with 4.75"-5" barrels.  This is pushing the envelope of the brass based on chamber case support and actually some have blown out the primers.

Ahh I knew there had to be a catch.  Oh well, I appreciate the info.  Trying to get my hands on some Underwood Gold Dot 155 or 165gr BJHP's as these seem to be the best choices for 10mm SD ammo.  Also need to get some 200/220 TMJ's or XTP's for inawoods activities.

[The_Shadow]

The Speer Gold Dots are another good choice, if there were some HST offerings (projectiles not offered as components other than from pulled 40S&W) would also make a great SD round from 10mm.

But hey if the perp is not wearing a vest, they aren't bullet proof!  There are cast HP bullets that would actually work well.

[ak585479]

The Speer Gold Dots are another good choice, if there were some HST offerings (projectiles not offered as components other than from pulled 40S&W) would also make a great SD round from 10mm.

But hey if the perp is not wearing a vest, they aren't bullet proof!  There are cast HP bullets that would actually work well.

HST's!!! Best SD bullet available imo.  I carry 7+1 230 grain HST's in my CCW (XDs .45).  I was so disappointed when I found they weren't offered in any 10mm cartridges.  So you're saying they won't even sell .40 HST projectiles?  You actually have to buy a box of 40S&W HST's, literally pull the bullet out ofthe brass, then load it into a 10mm casing with whatever hand load you choose?  Is that even possible to reload a projectile that's been crimped already?  I know nothing about reloading but I'm gonna (try to) start soon and buy reloading for dummies or the equivalent ofthat book 

BTW the cast rounds shouldn't be fired from a stock glock barrel correct?  Because of the weird rifling I think?  So I'd have to grab a lone Wolf barrel for cast bullets.  I was probably going to get a 6" barrel anyhow .

[The_Shadow]

Every once in a while, RMR http://www.shop.rmrbullets.com/ will get a run of pulled HST bullets, they will have some pulling marks on them but still perform well.  I've only seen them offered in the 0.400" caliber so far and they usually don't last long.

The crimp marks usually don't affect the reloading of the rounds, however plated rounds if they are crimped too deep, it can cut through the plating...that is not good!

Glock says no to lead or reloaded ammo as their policy.  Polygonal rifling is used in quite a few makes of guns.  About the cast bullets, I shoot my cast bullets from my factory Glock barrels, and accuracy great.  Care and inspection is needed, looking for lead build up or shaved bullet material at the end of the chamber that can prevent full chambering of the rounds.  Bullet Fit and quality lube helps.