Does velocity matter?

[Super-Dave]

Does velocity really matter? Lets take two bullets.

The 9mm 124 grain gold dot with a muzzle velocity of 1220

The .357 sig 125 grain gold dot with a muzzle velocity of 1375

Now according to gel testing found on the web both bullets penetrate to the same depths and have basically the same expansion.

Do you gain anything with the extra 150fps velocity? I know that you could penetrate hard barriers better but is that the only advantage?

This same question could be applied to 10mm and .40

Is there any real benefit to the extra recoil and velocity?

 

[EdInk]

It helps with HP expansion.

 

[Super-Dave]

Well for the above gold dot example the 9mm reliably expand already.

So is anything really gained?

 

[Hook686]

I think the squared of the velocity contributes to energy available for breaking chemical bonds in tissue. Thus the higher velocity bullet is capable of more tissue damage.

I also think the higher velocity will result in more momentum, which on identical paths ought result in more pentetration.

How much greather this increased velocity would amount to, I do not know. However I am one who believes that increased velocity cannot hurt, unless you cannot handle the recoil. Then it might be a case of diminished returns.

 

[Rifleman1776]

The recipient isn't going to argue about the 150fps difference.

 

[EdInk]

In that example the velocity was enough to give proper expansion.
The difference is going to be material pentration.

 

[SIGSHR]

I thought velocity was the difference between a 38 Special and a 357.

 

[BigJimP]

I knew he didn't want a serious answer SIGSHR ....

Of course it matters Super ...come on man ....

 

[Daryl]

The laws of physic's dictate that two identical bullets of the same wieght, expanding at the same rate and to the same diameter, but at different velocities cannot have identical penetration in identical materials.

So something has to be different.

In this case, I'd suggest the rate of expansion is different if all eise except velocity is equal. IOW, the faster bullet will have to expand at a faster rate, and reach full expansion sooner than the slower bullet in order to penetrate the same depth.

The faster expanding bullet (the one with highest velocity) will cause more trauma to the target by reaching the same diameter earlier in it's penetration.

 

[rjrivero]

The difference is in the wound cavity......

LINK HERE.

RJ

 

[Super-Dave]

I thought the temporary stretch cavity in a handgun round was really irrelevant.

 

[aroundchicago]

That 150 fps may not sound like much but it is almost 14% more velocity. I consider that a fairly significant difference.

 

[Daryl]

I thought the temporary stretch cavity in a handgun round was really irrelevant.

But the permenant one isn't. If a bullet expands faster so that it slows down quicker, and thereby has the same penetration, then the permenant wound channel will be larger.

Daryl

 

[Webleymkv]

I thought the temporary stretch cavity in a handgun round was really irrelevant.

Temporary cavity isn't always a reliable factor in handgun effectiveness, but it's not entirely irrelevant. Temporary cavitation can cause permanent injury in certain, more delicate tissues but not in others. Temporary cavity is good, but it shouldn't be relied upon to the point that placement and/or penetration are sacrificed.

As to your example of the 9mm and .357 Sig Gold Dots, I suspect that they are not identical bullets. One of the early problems with the .357 Sig cartridge is that it used 9mm bullets. While these bullets performed just fine at 1100-1250fps, they had issues with overexpansion, fragmentation, and shallow penetration when driven at 1400-1500fps in the .357 Sig cartridge. These issues were resolved by redesigning the bullets for higher speeds and/or dropping the velocity of most .357 Sig loadings to approximately 1350fps.

When properly designed bullets are used and velocity differences are significant, higher velocity cartridges can offer markedly different performance than lower velocity ones.

http://www.brassfetcher.com/Buffalo%20Bore%20125gr%20Speer%20Low%20Velocity%20JHC.html

http://www.brassfetcher.com/124gr%20+P%20Speer%20Gold%20Dot.html

http://www.brassfetcher.com/Speer%20125%20grain%20Gold%20Dot%20hollowpoint.html

 

[Cheapshooter]

The difference is in the wound cavity.....

Ballistic gelatin penetration and wound channel comparisons are of limited use at best. They would be the comparison needed if all BGs were made of the stuff. Most likely though, BGs are made of skin, muscle tissue, organ tissue, and bones. Ballistic gel gives a basic comparison, but stopping a scumbag intending to do you harm is still best accomplished with shot placement, and enough penetration to reach the central nervous system (spine).

 

[crghss]

The .357 sig is traveling 12.7% faster then the 9mm. So lets apply that to a car if you hit a telephone at 70 mph instead of 79 mph. Either way a hell of a lot of damage will be done. But you have a better chance of surviving a 70 mph crash then a 79 mph crash.

 

[WC145]

Think in terms of a formula like mass x velocity = impact energy.
Similiar mass x higher velocity = greater impact energy.

The bullets, though similar in weight are not the same. One is designed to expand at 1220fps, the other at 1375fps. Bullet expansion slows it down to keep it from blowing through the back of the target and allows it to impart it's "impact energy" into the target medium. A bullet of similar weight and design, traveling faster but dumping it's energy in the same distance, will do more damage to that medium than the slower bullet.

 

[Casimer]

Here's the kinetic energy equation..

So yes, velocity matters.

 

[totaldla]

I guess your research shows that it doesn't matter if you are attacked by blocks of gelatin.

 

[Jim March]

I carry 357Mag 125gr that will hit closer to 1,600fps from a serious barrel length. THAT might possibly do "abnormal stuff" like shatter bone if it hits it on the way in.