1000, 1100, 1200.... difference?


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PT1911
April 13, 2009, 01:38 PM
so I hear this a lot.


"Only 1200 FPS, that just isnt fast enough"

I understand that something moving at 4000 FPS is going to do much more damage than something moving 1000 FPS, but that is 3000 FPS difference and something different altogether. what is the real advantage of an extra 100 FPS or 200 FPS?

I cannot imagine a bullet that doesnt penetrate and "mushroom" at 1200 FPS and magically spreading wider and going farther with an added couple hundred FPS....:confused:

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30.06
April 13, 2009, 02:21 PM
I believe the 1200fps idea came from years ago , when all the various bullet makers were just beginning , to make Jacketed Hollow Points , for various handgun calibers .
After years of trying different styles/ideas , they finally learned , how to make handgun bullets , giving the desired expansion without having to blast them into the target at high velocities .
There was something , to needing 1200fps , to get fairly reliable expansion with many of the early bullet designs , but I believe that difficulty has been overcome in the last fifteen to twenty years , by all the good bullet manufacterers .
I have confidence that many of the modern bullets will expand reliably at as little as 800fps .
Progress quite often goes backwards and does not work to improve things , but in the case of current expanding bullets , real progress has been made .

PT1911
April 13, 2009, 02:26 PM
thats what i thought.... why the obsession with an added couple hundred fps?

TexasRifleman
April 13, 2009, 02:31 PM
It is claimed that for bullet velocities below 1600fps slight changes in velocity can impact the ballistic coefficient drastically.

Way too much math for me but....

http://www.exteriorballistics.com/ebexplained/5th/24.cfm

The 1200fps number is probably thought of as "magic" because it's close to but still above the speed of sound, 1120fps.

JWF III
April 13, 2009, 04:49 PM
It all comes down to bullet design.

Lets look at .38 spec./.357 mag. You have the exact same bullet diameter and weight, but speeds that range from 700 fps to 1700 fps. A bullet designed to open up at the lower end of the spectrum will likely disintergrate if impacting something at 1700 fps. But a bullet that was designed to handle the upper end, will not reliably open at the lower end.

Now lets take one bullet that is designed with an optimum velocity of 900 fps, and a max impact velocity of 1400 fps. Granted for SD situations, 950 fps would do just as good as any other velocity. But for hunting, or any other situation where range is going to be variable; the faster the muzzle velocity is, the longer the bullet will stay above (or in) the range the bullet is designed for. So if you're expecting your range to be 25 yards to 150 yards, having a cartridge that pushes that bullet at around 1425 fps will give you optimum performance for your situation. But if you're expecting only longer shots, you could increase the velocity. Then your optimum range (bullet speed & target distance) will increase

In laymans terms, the faster the bullet leaves the muzzle, the faster it will be going when it reaches the target. If your chosen bullet is designed to open at a lowest speed of 900 fps, and your load drives it at 1000 fps. You will not have adequte performance past 50 yards. And at 100 yards, the bullet will fail to expand.

But as I stated, for a SD situation, where ranges will be close, all of this is null and void.

Wyman

PT1911
April 13, 2009, 08:51 PM
thank you... that clears it up quite a bit... I appreciate your responses...

GRIZ22
April 13, 2009, 08:58 PM
thats what i thought.... why the obsession with an added couple hundred fps?
__________________

I feel the same way. The fascination with +P and +P+ is a good example. Most of these loads only get you 100-150 fps if that much (according to chronograph not what the manufacturer says). I will admit to using +P in K frame size 38s but it seems to me if I really what something hotter I'd go a 357. Need a +P+ 9mm? Go to a 357 SIG or 38 Super.

Kind of Blued
April 13, 2009, 09:26 PM
Good synopsis JWF III.

I've often thought about the possibility of a supersonic crack causing additional hearing damage in an indoor SD shooting, but I've always assumed that the difference in dB is negligable, especially with the report of any legitimate SD cartridge.

I've always found it interesting that the .357 Magnum is widely-considered to be the ultimate "manstopper" if you're talking traditional handguns, while the same thing going a "few hundred fps" slower (.38 Special) is considered marginally acceptable for self-defense these days.

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