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After many shows of looking for it, at Market Hall a week or two ago, I picked up a couple of boxes of the 124 grain +P stuff with the "Short Barrel" designation.

This morning a lady student came out to do some more break-in on a new Kahr CW9, so I set up the chronograph in advance and used the opportunity to do the testing below. The "standard velocity" shown is the same 124 grain load I've had in PM-9 for several years. The CW9 had only 100 rounds total of WWB down the barrel before the Gold Dots were fired. The other 2 pistols are far more broken in and were semi-dirty at the time.

edited to add: Sorry, I can't get the columns to format here, so just going to move "diffence" out by itself.
edited to add: that did not work either. 113 64 101 !!!

4-26-08 Gold Dot 124g 9mm

Std. Vel. +P "Short Barrel" Difference

Kahr PM-9 (2 3/4") 991 1,104 113 fps

Kahr CW-9 (3 1/4") 1,119 1,183 64 fps

Glock 19 (3.85") 1,121 1,222 101 fps

Not to be a "party pooper", but I think need some more data, such as the number of rounds fired and the mean and standard deviations of the velocities to determine if there is a significant difference. I am not a statistician, but there are some people in the forum who could analyze the data for you.

Standard deviation and such is somewhat beyond the KISS method. Once I cleared that stat class in college, I never wanted to hear of such again.

The instrument will do all of that - if time and interest. I just recorded 5 (expensive!) shots each manually, then pulled "average" (excuse me, "median" ) with calculator in trying to clear the range quickly for others. We did shoot a few WWB just to make sure everything was running and the spread there was pretty horriffic: 937 up to 1,141. The Gold Dot stuff was quite consistent - 30 fps or so max, some in single digits.

My point is that you need to shoot at least one box of each type of ammo in each barrel configuration to get a significant result. I know the KISS method is easier, but I wouldn't shell out the extra money for ammo based on only five data points.
I know just enough statistics to be dangerous.

A consistent 10% difference such as you saw probably is significant.

frankie_the_yankee wrote:A consistent 10% difference such as you saw probably is significant.

I will defer to Frankie, but we don't know if it is consistent for a large population since the test was performed once with only one gun. Your mileage may vary.

"I know just enough statistics to be dangerous. " Same here with electricity.

I think the even "purists" might accept 10 rounds of each type per barrel - and I'd shoot 'em - or 20 for that matter if they want to provide the ammo.

Scarcely any diffence in the price on the rounds tested. Boxes of 20, at right at $20 to $22 per box depending upon when and where bought. That why I figured 5 apiece would be was just dandy

Interesting. I tested standard 124gr +P Gold Dot out of a Glock 26 and got 1242 fps avg.

I carry the Gold Dot 135gr +p short barrel .38 Specials in my S&W 642 and have been very pleased

Gary -

Those well worn 26s do seem to spit 'em out pretty fast - for what they are. Check this out:

4-25-06 Winchester Ranger 127g 9mm +P+

Wallace Glock 26 Avg. fps: 1268, Wallace Glock 17 Avg. fps 1372 fps E.S.:18, S.D.: 7

LW new (25 rounds prior) Glock 19, same Ranger +P+ ammo, different box: avg. fps 1218 ( ! ? ! )
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Cam - FWIW, Similar 38+P load that you mentioned went at 824 out of my 340 a few weeks ago. I had located a box each of the official "short barrel" versions in 38+P and .357 a couple of weeks ago, but when I got to Bullet Trap to buy, sold out ...

Greybeard wrote:Gary -
Cam - FWIW, Similar 38+P load that you mentioned went at 824 out of my 340 a few weeks ago. I had located a box each of the official "short barrel" versions in 38+P and .357 a couple of weeks ago, but when I got to Bullet Trap to buy, sold out ...

I picked mine up online through Midway USA with a bunch of other stuff. Sometimes they're backordered, but usually in stock.

Greybeard wrote:Scarcely any diffence in the price on the rounds tested. Boxes of 20, at right at $20 to $22 per box depending upon when and where bought. That why I figured 5 apiece would be was just dandy

If the price is the same, then you have nothing to lose.

It looks like Speer considers a barrel less than 4 inches to be "short." I am curious how the short barrel ammo compares with the normal ammo in a long barrel.

I chronoed the .45acp 230 Short Barrel in my Kahr P45 with a 3.5".

It was consistently 50fps slower than old fashioned Hydra-Shok 230's.

I carry the Gold Dot 135gr +p short barrel .38 Specials in my S&W 642 and have been very pleased

You should be. They will penetrate as far as the 124 grain 9mm GDSB's, which penetrate about twice as far as Remington GS 124 grainers in my limited ballistic testing experience. Here is stunning testament to the efficacy of the .38 Special from one of the world's most violent cities: http://www.sfgate.com/cgi-bin/article.c ... 109T9M.DTL