Ever wonder how much barrel lenth affects bullet velocity?

[TheTman]

Then Ballistics by the inch (http://www.ballisticsbytheinch.com/) might have the answers you are looking for. They ran tests on all the major handgun calibers, using mostly Cor-Bon and Federal Ammo, with barrels from 2" inches up to 18".
I found a few interesting and surprising results.

[Bawanna]

Interesting to note the velocity seems to increase as length is shortened, then peaks and begins to drop off.

Like the 45ACP Federal JHP. Starts out a 888 with the 18" barrel, climbs to 948, then drops down to 709 with a 2".

Guess every caliber has it's little sweet spot.

The overall loss due to short barrels at least to me is far less than I would have anticipated.

Thetmanski, thanks for posting this. Good stuff.

[jpshaw]

Basically velocity will increase with barrel length until you reach the point there is no more powder to burn then its starts to slow down from barrel friction. I know a .22 LR will peak around 14 to 18 inches. So a long barrel pistol will have more velocity then a short barrel one but a short barrel rifle will have more then the long one in .22 LR. I'm sure pistol ammo will peak somewhere around there also.

[jocko]

and I guess one can take all that info and put it in his data base to help make a decision but the bottom line is most peopel today seem to be after a small ass 9mm and even 40 cal if possable, so there is going to be some give and take to achieve both. and yes for your 45 guys even a smaller PM45 if possable...In as much as 99.995% will never have to worry about whether one had enough velocity if used in a defense situation and your after a small ass gun, then pick one of the many out there and just forget about all that other stuff and shoot it like you stole it.

Ammo today compared to 20 years ago has made leaps and bounds in performance..

[wyntrout]

I pointed it out before, but they did some more testing last year and added some .380 tests with more ammo and real world tests including all of the now popular .380's, including the P380. Buffalo Bore rules! See the energy tables as well.

They have the Speer 124-gr GD +P Short Barrel tested as well in the 9mm section. Great info!

Wynn:)

[garyb]

Interesting stuff themanski and thanks for sharing. I always find it interesting to look at performance stuff....just so I know what is happening.

I agree with everything you've said Jocko. Once you have the gun (and I did pick the PM for the reasons you;ve pointed out), all I could do after that was to pick the ammo I was confident in and there's lots of good stuff out there.

[jlottmc]

It is interesting, I was surprised by a couple of mine, but that's how it goes.

[JodyH]

60 degree ambient temp, measured at approx. 3 yards from muzzle, average of 5 shots

Kahr PM9 3" barrel.
Winchester "value pack" FMJ: 1032 fps
Winchester Ranger 127gr. +P+: 1129fps

H&K P2000 3.7" barrel.
Winchester "value pack" FMJ: 1133 fps
Winchester Ranger 127gr. +P+: 1232fps