Longslide Ballistics

[MPG1737]

I am curious if anybody has any data on the fps increase provided with a 6" barrel (vs. a 4").

I am especially curious about the standard pressure loads. The idea of +P ballistics from standard pressure loads is appealing to me.

;c

[wekivaGLOX]

i figure an extra 50 fps per extra inch, to err on the side of slower. I've never clocked it though.

[ffcracker]

I do not have any hard numbers but I found this. In the '99 Glock Annual it states:

You can expect a 7% to 10% increase in the G34 over the G17.

You can expect a 2% to 6% increase in the G35 over the G22.

It has a bunch of velocity numbers but I do not have time to type them all right now. That and they are going on 6 years old so some of this ammo might not even be produced anymore.

[MPG1737]

I can work with those numbers. I figure it would be reasonable to change a 7% gain to 8%, and 10% to 11% when comparing the G34 to the G17L. ;c

[bdc]

Expect to gain a greater percentage gain in velocity and power from slow burning powders. Muzzel blast from longer barrels is much reduced from that experienced with short barreled guns using the identical slow powder loads.

Fast burning powders are designed to exhaust their chemically bound oxygen within short barrel lengths, so longer barrels offer little performance gains with these powders.

[sv1krider]

Check out this review that has a paragraph specifically about velocity. Hope it helps.

http://remtek.com/arms/glock/model/9/17l/

[cmzneb]

I have chronographed some of the same loads in a G27 and G35. They are a light target load.

G27 = They ran an avg. 739 fps
G35 = They ran an avg. 778 fps.

[32Special]

I recently chronographed some old 180 grain Black Talons and some 180 grain Speer Gold Dots from my G24. Velocities for both were about 1080 fps. FWIW.

[ColoradoGlocker]

.

[Rob1035]

old thread, but I got some info you all might be interested in:

I asked Double Tap about their 9mm from a longer barrel, and got this response:

From a 5.5" bbl:
115gr: 1497fps
124gr: 1395fps
147gr: 1241fps


Not too shabby, eh?

[ecmills]

Hard numbers from Caliber Corner:

http://glocktalk.com/showthread.php?s=&threadid=522564&highlight=g34+barrel

Good read.