This is a discussion on Barrel Length and Velocity, a little data within the Defensive Ammunition & Ballistics forums, part of the Defensive Carry Discussions category; I did some "testing" (it was mostly messing around) with my chronograph last week, and I decided to chrono some factory ammunition in different barrel ...
I did some "testing" (it was mostly messing around) with my chronograph last week, and I decided to chrono some factory ammunition in different barrel lengths to see how much velocity change I got. So, here is a little of what I found:
Federal Classic 125 grain SJHP .357 Magnum, Average velocity:
2 1/4" Ruger SP101: 1293 fps
4" S&W 681-3: 1429fps
Speer Gold Dot 125 grain Gold Dot .357 Magnum, Average velocity:
2 1/4" Ruger SP101: 1242 fps
4" S&W 681-3: 1392 fps
Winchester Ranger T 230 grain .45 ACP, Average velocity:
Glock 36: 844 fps
S&W M&P45 (4 1/2"): 869 fps
The .357 testing resulted in basically what I expected. On the other hand, I expected to see a lot more velocity lost from the short Glock 36, but it only lost 25 fps to the longer barrel M&P.
Just a little food for thought.
"The Engine could still smile...it seemed to scare them" -Felix
Good food for thought. Glad you brought this up.
It's only been a notion of mine but, in playing around over the chronograph with any of several .45 ACP revolvers and automatics around here along with shooting others' pistols and carbines for velocity, it seems that the .45 ACP has a tighter velocity range in which it operates than many other handgun cartridges.
Perhaps it is due to the relatively low operating pressures. The 9mm demonstrates more velocity fluctuations when fired through various length barrels but then it operates at much higher pressures than does the .45 ACP.