Observations from Tnoutdoors9 Test
 

If you watch his videos you can start to pick up on certain trends. I notice bullets that achieve >1000 fps seem to cause more internal damage than bullets that achieve <1000 fps. The slower bullets seem to just punch a straight path and not "churn" up the gel.

Some of the Underwood Ammo 10mm offerings in the 1500-1600 fps range produce a damage path that looks similar (not the same) to a .223 damage path.

I think that velocity and bullet construction is playing a bigger role in the wounding abilities of these bullets than the actual size of the bullet.

Categories.

115 grain+ weighted bullets >1250 fps

115 grain+ weighted bullets >1400 fps

124 grain+ weighted bullets >1200 fps

124 grain+ weighted bullets >1250 fps

165 grain+ weighted bullets >1000 fps

200 grain+ weighted bullets > 850 fps



Each individual category has some tradeoffs.
115 grain+ weighted bullets >1400fps produce a large damage path but also produce shallow penetration.
124 grain+ weighted bullets >1200 fps offer a balanced mix of large damage path and adequate penetration.
165 grain+ weighted bullets >1000 fps create adequate penetration, but not always a large damage path.

200 grain+ weighted bullets >850 fps penetrate deeply, but do not produce a large damage path.

In regards to 155 and 165 grain bullets traveling >1150 fps, I don't have enough data to make any meaningful observations.

With the data produced by tnoutdoors9, I can make a few hypotheses:

The best all-around performers based on the data available, appear to be 124 grain+ weighted bullets >1200 fps and 165 grain+ weighted bullets >1000 fps.

This could change with additional testing of 155 grain bullets traveling at 1300/1400 fps, 165 grain bullets traveling at 1200/1300 fps, and 180 grain bullets traveling 1100-1300 fps.

Testing of the Underwood .45 ACP 185 grain GDHP at 1200 fps and 230 grain GDHP at 1000 fps would be interesting and are necessary missing data points.

The only conclusion I can draw from the current data points is that 1000 +/- 25 fps seems to be a threshold for creating a damage path. Bullets moving slower than 975 fps appear to mostly push straight through.

These are just my observations. These could also be meaningless as simulating actual live tissue is much different than a ballistic medium.

I like mid-weight, fast, bullets personally, at least in 9mm. I do think energy is a factor.

That said, pistol bullets at these velocities simply do not create damage from the temporary cavity. Only tissue that is physically touched by the bullet is permanently damaged. .357 Sig consistently produces the most impressive permanent cavities, especially in overall length of the large permanent cavity (typically around 7 inches).

This is a good read:

http://www.firearmstactical.com/hwfe.htm

The damage to the gel is what I am basing my observations on. I'm not even jumping into the ballistic pressure wave game.

The gel damage, or "churning" as you put it, is an indicator of temporary stretch cavity. Now this is a long-running debate on here as to whether it has any impact on incapacitation by being strong enough to actually tear organs not specifically touched by the bullet itself. I dunno personally......I'm on the fence. Always have liked a "dynamic" bullet, but some of these newer bullet designs like HST don't need a screaming velocity to perform as far as expansion and penetration are concerned. :dunno:

The ballistic pressure wave is more concerning "shock" to the CNS or cardiovascular system from a wave of pressure.

Frankly I'd put more likelihood of actually occuring on the temporary stretch cavity causing additional damage than I would the ballistic pressure wave slapping someone down.

Where the gel has been "churned" that indicates damage. In a scientific format, that equals more damage.

These two things you mention go hand in hand.

You post those links so much you must be sold on the koolaid, very, very old koolaid at that.

I think the first one is at least *possible* with handgun rounds, the BPW probably not unless we start talking about the next level, i.e. rifles.

Like I said, they go hand in hand. The peripheral wounding of a bullet is also caused by said wave. It is not as simple as just rifle or pistol rounds. It is also not just as simple as more or less velocity, it is the rate of transfer which coincides with bullet construction. Do rifles have it easier because of higher energy levels? Yes. But it is a lot of factors and how they work together that makes the difference. Pistols have the same capabilities (within reason) but must transfer much faster since they start out with less energy. Anemic rounds will have the most trouble with this since they cannot spend themselves on rapid expansion to gain a decent temp cavity and hope to have enough left for a desirable penetration depth.

I'm a fan of accuracy, speed, and penetration. This is my reason for going with a 155gr XTP handloaded in a 40S&W. The 155XTP has good velocity (1150-1200fps depending on load), it expands (not as much as some), and you get stellar penetration. I'm also getting more consistent, and excellent accuracy from my handloaded 155XTP's @ 1150fps (haven't tried higher velocity YET) than any other store bought whiz bang round that you can get at your LGS. TnOutDoors has tested the XTP bullet in GEL using the Hornady TAP load, and it performed impressively based on the criteria I look for in a handgun cartridge.

This coincides what ive been saying for years and have seen quite a bit first hand. The 357sig is the best handgun caliber on the planet, for all around self defense.

Yep... it's done a pretty good job of duplicating one .357 magnum load on the light end...

:upeyes:

10mm stomps the 357sig between bullet diameter, bullet weight, and velocity. :tongueout:

Plus I'll take a 40S&W 155gr moving @ 1200fps in a 4" barrel over a 9mm 125gr bullet moving @ 1350 in a 4" barrel. But that's just my preference. To each their own.

The gel isn't "churned". The path you see carved out is where the bullet has cut through. There is also going to be variability in how he slices the halves. You'll notice he uses that little pick thing to pry open the damage channel so it can be seen better.

Why do you think the maximum cavity isn't produced until several inches in? Because the bullet hasn't fully expanded yet! The damage is only being caused by what the bullet is physically touching. If temporary cavity/energy was causing damage you would see more damage at the entry point because that is where max energy is occurring but all you see is a wound track the diameter of the original caliber.

BTW, his .40 180gr HST test was one of the best for wound channel, in any weight or caliber.


What more proof? Look at one of his few videos where he shows front facing cross-sections of gel. The only damage is where the shaft of the bullet and the petals have cut through. For example, watch this starting at 3:30:


BUT... the .357 Sig videos do show some evidence of the temporary cavity actually permanently deforming gel outside of the permanent cavity. So anyone dissing the .357 Sig hasn't been paying attention.

Well, that "light end" is where the legend of the .357 Magnum lives.

This is why I have begun to favor the 357Sig of the 1400+fps variety (Underwood, Cor Bon, and despite my recent experience, DoubleTap too). *If* this extraneous damage is going to occur it's going to be with a very dynamic round, i.e. quite fast with a quick energy dump. I'd go as far as saying a 155gr .40 pushing 1200+fps would get it done too with the right bullet.

According to his data, I need not worry about over-penetration with my +p+ 115gr JHP 9mms, even though they are likely going over 1400 FPS.

:dunno: You literally contradicted yourself all in one post.

Anyway, you can see temp cavity effects with other rounds he has tested, the 10mm 180grn GD being a good example. The bullet clearly does not touch the media an 1" (2' dia.) away from the bullet track yet there is damage...

Agreed.

In a perfect world physics would determine our handgun/ammo choices. The catch is that what is evident in static calibrated gel doesn't reflect the myriad factors that go into each and every self-defense scenario.

All things being equal, (e.g. reliable consistent mushrooming of the bullet) the faster a bullet of any given caliber delivers its energy the greater its effect as long as the bullet remains in the target. But the variables in self-defense shootings are so numerous that I doubt there will ever be a perfect world answer all of us would accept.

One day I am going to chrono this load. :cool:

"Churned" may have been a poor word choice, but cutting is more accurate. There is more evidence of tearing at 1000+ fps. The slow moving .45 slugs simply push right through the gel. Even when he shows the cross section of the .45 rounds, there is no actual gel disruption. The sections fold back together. With the faster rounds there is some evidence of tearing in addition to cutting.

From what I've seen in his tests, 1220-1250 fps seems to be the starting point at any sort of temporary cavity damage. Still it appears to be minimal. There is more evidence of tearing and cutting though.

Or the only part of the legend you've payed attention to...

It's a very capable woods round as well with 158's or 180's. Has been since 1934.

http://i561.photobucket.com/albums/s...29-2/357ad.jpg

True story. :goodpost:

Okay, it has like a carbine-length barrel! SBR anyways......