What is "rifle velocity"?

[WS6]

Where does rifle velocity begin? Terminally, I mean. To the point where permanent crush-cavity of tissue actually touched by the projectile is not the only wounding mechanism?

Is there a "barrier", such as a 50-150fps or something range at which a rapid transition in wounding mechanism takes place, such as:

13-1400fps = Crush cavity only
1450+ = TC causing permanent meaningful injury as well

Does it "taper off", for example, a wound caused by a projectile at 2700fps doesn't look much worse than one caused by the same projectile at 1700fps (barring fragmentation or more robust expansion of course)? Or will a wound caused at 1700 fps be meaningfully less severe than one at 2,000 fps, and then 2200fps, and so on?

*All of this line of questioning assumes a non-fragmenting, robustly expanding bullet like Barnes or Gold Dot.

[DocGKR]

Assuming the parameters you noted, somewhere around 2000 fps or so, the TC starts getting large enough to produce significant stretch injuries, but keep in mind it is a continuum. TC also depends on the size of the projectile--some slower expanding .45-70 and .44 Mag loads, as well as 12 ga slugs can also create an impressive amount of stretch damage at lower velocities.

[WS6]

Assuming the parameters you noted, somewhere around 2000 fps or so, the TC starts getting large enough to produce significant stretch injuries, but keep in mind it is a continuum. TC also depends on the size of the projectile--some slower expanding .45-70 and .44 Mag loads, as well as 12 ga slugs can also create an impressive amount of stretch damage at lower velocities.

My angle is...is a 300BLK 110gr TTSX a 9mm pistol that does OK against body armor, past 100 yards?

Velocity at 100 yards when fired from a 9" barrel: @1900fps (based on @2200fps MV, and .295BC)
Exanded diameter: 0.585
http://i134.photobucket.com/albums/q...iersummary.jpg

That falls below "rifle velocity", and the expanded diameter is solidly in "decent 9mm" performance range.

Have I purchased a really accurate shoulder-fired 9mm pistol? We all agree that a 70gr TSX from a 5.56 is far superior to the 9mm in any flavor. Should I stick with a 5.56 in 10.5" barrel (around 2500fps with the Brown Tip I have), terminally, as opposed to 110gr TTSX from my 10.3"? Why/why not? The "raw data" suggests that the 5.56 is vastly superior at this point, unless I am mistaken?

[AndrewWiggin]

Assuming the parameters you noted, somewhere around 2000 fps or so, the TC starts getting large enough to produce significant stretch injuries, but keep in mind it is a continuum. TC also depends on the size of the projectile--some slower expanding .45-70 and .44 Mag loads, as well as 12 ga slugs can also create an impressive amount of stretch damage at lower velocities.

Does that mean that some 10mm ammunition might benefit from the TSC as well? Say a 165 gr Gold Dot at 1,300 fps? There is certainly a lot larger stretch cavity from most 10mm expanding ammo than from service cartridges.

[DocGKR]

Generally 10 mm does not get there...

.300 BLK TTSX nicely expanded at 1900 fps is "somewhere around 2000 fps or so", as noted above...

While both work, I'd rather have a .300 BLK using 110 gr TTSX over a 5.56 mm using 70 gr TSX when fired out of a 8-10" barrel.

[AndrewWiggin]

When you said "size," were you referring to mass as well or just frontal area?

Is there any direct relationship between the size of TSC in gelatin and the likelihood that it will contribute to wounding in flesh?

[WS6]

Generally 10 mm does not get there...

.300 BLK TTSX nicely expanded at 1900 fps is "somewhere around 2000 fps or so", as noted above...

While both work, I'd rather have a .300 BLK using 110 gr TTSX over a 5.56 mm using 70 gr TSX when fired out of a 8-10" barrel.

I understand. At 200 yards, the 300BLK impacts at less than 1700fps. Does this mean that its maximum effective range...performing "as a rifle"...is somewhere south of 200 yards? When fired from a 9-10" barrel? ( I know it will expand down to around 13-1400fps, but that's 9mm velocity).

[kenndapp]

I have been questioning weather the 110gr tsx performs closer to a riffle round or pistol round out past around 200 yards for a while now. Good thread. I'm sticking around to hear this one. Thanks.

[Symmetry]

I just joined up, and so far the Terminal Effects section is the most interesting. I've read lots of Fackler's work, along with some other interesting reads like Duncan McPherson's book.

DocGKR,

I take it that the temporary cavity stretch would be enlarged by factors such as caliber size, ogive length, and meplat diameter in a non expanding handgun caliber. Just like the M1 Carbine FMJ? When it comes to the stretch cavity in a handgun bullet, what would effect it more?........a .357" JHP traveling at 1500fps, or a .451" JHP traveling at 1000fps? I'm just curious if a pistol carbine could be setup with custom loads to achieve any viable TSC.

[Clint]

I believe this effect is related to the speed of sound (mach) in gel/flesh.

Objects traveling faster than Mach in a media produce a shock wave.

Speed of sound in air is ~1100fps,
Speed of sound in water is ~5000fps

I haven't been able to find anything about the speed of sound in gel/flesh, but it is reasonable to assume it is between 1100 and 5000fps, with the 2000 fps a good center point.

ETA: looks like the speed in soft tissue is ~5000 fps.
http://www.rfcafe.com/references/gen...ound-media.htm

ETA2: looks like the speed in lung tissue is ~1640 fps.
http://www.sambahq.org/clientuploads...0521515788.pdf