This is a discussion on Ballistics musing 9mm within the Defensive Ammunition & Ballistics forums, part of the Defensive Carry Discussions category; I have looked for data on the influence of barrel length on velocity/energy. Having not found anything to my taste, I created a chart from ...
I have looked for data on the influence of barrel length on velocity/energy.
Having not found anything to my taste, I created a chart from Glock data. Since it is from Austria, the units are metric.
Velocity in meters/second.
Energy in joules.
However the barrel length is in inches.
If you need to convert:
- velocity: meter/second x 3.32 = feet/second
- energy: joules x 0.738 = foot.pound
The dotted line is a linear extrapolation - constant pressure - not true but not very false .
One interesting fact I found was that by putting the G-19 barrel in my G-26 (9mm) the energy level is 5% higher than a G-27 (.40) and the muzzle velocity 23% higher (lighter bullet).
Both are way over the G-30 (.45 ACP - 3 3/4" barrel); of course, te ratio of barrel length to bore diameter, with short barrels penalize the larger bore heavily.
Just numbers; I don't want to start another "caliber war"
Extrapolating to revolvers, bear in mind that the barrel length of a revolver does not include the cylinder, so a 2" snubby compares to a 3.5" pistol. OTOH the cylinder gap takes its toll ...
Click on the thumbnail to see the graph.
If you know of similar data, please let me know.
The first rule of a gunfight: "Don't be there !"
The second rule: "Bring enough gun"
jfl (NRA Life Member/Instructor - GOA - IDPA - GSSF - ex-IHMSA)
Any time I see 'joules', I think of electricity. 1-10 billion joules would be in an average bolt of lightning. Sorry......just musing myself. I'm easily mused! ;)
Yep, no need to start another caliber war because we all know that tiny little holes are more effective than large gaping wounds.
Yeah, no need to start a debate. Besides, we all know 9mm is a better than a .45
I have both so let's not go down this road again.
1 well placed shot is better than 5 not so good.
It is a great way to see the difference between 4 inch and 16 inch.
Last edited by Darkwater; November 20th, 2008 at 12:57 PM.
Can't we all just get along?
I don't know, but all that math is making my head hurt.
When you've got 'em by the balls, their hearts & minds will follow. Semper Fi.