View Single Post
Old January 9, 2019, 01:25 PM   #19
stagpanther
Senior Member
 
Join Date: March 2, 2014
Posts: 11,655
Quote:
Quote:
6 or 8 inches longer of barrel for 20 to 40 fps more is not worth the added length to the gun or decreased rigidity.
Decreased rigidity? of the barrel??? I don't think that matters much in a 9mm or 10mm carbine.

and, 20-40fps gain from 6 or 8 inches more barrel is not a fixed number. Each gun is going to be a bit different about that, and the specific loads used will make the difference even more.

9mm is loaded to be optimized from a pistol (or SMG) length barrel, and does not gain as much velocity per inch from a longer carbine barrel, as some other cartridges do. But it does gain some. The OP got about 250fps increase from his carbine, over the listed velocity for the load. That's a bit more than 20-40fps...
I think what he meant was that the gain over the 8.5" barrel was only 20 to 40 fps.

So guess what? I'm going to take identical barrels with the same bore and chamber from the same manufacturer but at the different lengths and test the difference with the same ammo just out of curiosity and see for myself. Might take a few weeks--but I promise I'll post the results whatever they may be.

QL--which admittedly tends to be sketchy with pistol cartridges--tells me I should get an 100 fps or more.In a pistol bullet that is not an insignificant difference in the world of terminal effectiveness out to 100 yds.
__________________
"Everyone speaks gun."--Robert O'Neill
I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk!

Last edited by stagpanther; January 9, 2019 at 01:39 PM.
stagpanther is offline  
 
Page generated in 0.02417 seconds with 8 queries