Barrel Length and Chronograph Data

[FloridaCCW]

http://www.ballisticsbytheinch.com/9mmluger.html

[tracker]

What conclusions do you draw from these data?

[kjtrains]

http://www.ballisticsbytheinch.com/9mmluger.html

CCW.  Good information.  Thanks!

[FloridaCCW]

What conclusions do you draw from these data?

Still looking it over, but it Looks like +P ammo does not make much of a difference in 2-3 in barrels. The .32 versus .380 data is interesting in short barrels.

[yankee2500]

I's always been my thought that +P would do little more than a standard pressure round in a 3" barrel.

John

[yankee2500]

I thought there may be a little more difference in the short barrel rounds than there was but it is better than standard ammo.

John

[tracker]

~200 fps is quite a difference between the +P and standard in a 3 " barrel.

[FloridaCCW]

FPS can be misleading though when it comes to a wound profile. Be nice if they looked at how the FPS energy transferred to something    

[yankee2500]

Here are the real apples to apples comparison straight from the Speere site.
  The short barrel 124 gr ammo is listed as +P and is no faster than the standard pressure 124gr Gold Dot and slower than the non short barrel 124 gr +P. And has the same muzzle energyas the standard Gold Dots.
(There test barrel is 4")


Gold Dot Short Barrel Personal Protection - 9mm Luger +P
Part Number      Cartridge
Bullet Wt.      Bullet Type       Box Count      Bullet Coefficient
23611      9mm Luger +P      124      GDHP-SB      20      0.134

Velocity(in feet per second) (foot pounds of energy)
Muzzle ------------------------Muzzle      
1150 --------------------------364      


Gold Dot Personal Protection - 9mm Luger +P
Part Number      Cartridge
Bullet Wt.      Bullet Type       Box Count      Bullet Coefficient
23617      9mm Luger +P      124      GDHP      20      0.134

Velocity(in feet per second) (foot pounds of energy)
Muzzle ------------------------Muzzle      
1220 --------------------------410


Gold Dot Personal Protection - 9mm Luger
Part Number      Cartridge
Bullet Wt.      Bullet Type       Box Count      Bullet Coefficient
23618      9mm Luger      124      GDHP      20      0.134

Velocity(in feet per second) (foot pounds of energy)      
Muzzle ------------------------Muzzle
1150 --------------------------364  

Here is the link to the Speere site.

http://www.speer-ammo.com/ballistics/ammo.aspx   


John

[FloridaCCW]

Good info

[kjtrains]

I've read somewhere that in a short barrel the +P bullet is unable to reach its full velocity potential so, therefore, is a waste, so to speak; in the 124 gr. +P bullet full potential being 1220 fps.

And John.  Good information, as well.

[tracker]

It we could use the +P in the R9 I would go with the 410 ft/lbs vs. 364 in a carry situation but that is a moot point. There is at least a 10 per cent difference in a 3" barrel between the two.

[kjtrains]

Yep!  No use discussing the +P for the R9.    

[Reinz]

I've read somewhere that in a short barrel the +P bullet is unable to reach its full velocity potential so, therefore, is a waste, so to speak; in the 124 gr. +P bullet full potential being 1220 fps.

And John.  Good information, as well.

KJ is correct.


This is the whole key here.

It depends upon which particular cartridge you are using because it MAINLY depends upon if ALL  of the powder  has enough time to get burned while that bullet is traveling down that short barrel  to acheive it's full potential velocity.


Fortunately with newer powders/blend, the newer ammo put out today does a better job in shorter barrel guns.
Used to, +P was not worth a hill of bean in a 4 " gun.  Now they seem ot be working pretty well.  Is + p   ready for 3" yet ? or sub 3". Maybe, maybe not, but I think they are doing a good job working their way down.

[yankee2500]

It becomes a catch 22 situation, the faster the powder burns the more pressure it creates. So trying to push a bullet faster in a short barrel without going into a +P situation is a difficult task.
  You wouldn't believe how much unburned powder is on the floor at an indoor range.

John