I had my first outing at the range to use my new Garmin Xero C1 Pro chronograph (I'll review that separately). One of the tests I wanted to do was the Federal 9mm HST 124 gr +P ammo that I use in two different pocket guns, the Kahr PM9 and the S&W 940-1. I wanted to see what the velocity would be in these short-barrel guns, and what kind of velocity loss there might be in the revolver with the barrel/cylinder gap versus the semi-auto. I was surprised by the results.

Here's the five-shot results for the Kahr PM9, with the stated 3.1" barrel:

1,064.9
1,153.6
1,122.6
1,112.5
1,112.9
Five-shot average: 1,113 fps, with energy of 341 fp.
Here's the five-shot results for the S&W 940-1, with the stated 2" barrel:

1,123.7
1,174.0
1,142.4
1,168.9
1,148.5
Five-shot average: 1,151 fps, with energy of 365 fp.

I was pretty surprised by the results. They're virtually identical, with the revolver winning out by a little bit. While the PM9 has a stated barrel length of 3.1", we know that the true barrel length for bullet travel purposes is 2.35" (3.1" - 0.75" case length), while the revolver is a true 2". The revolver also has the free-run length of the cylinder length for the bullet to travel before it makes the jump to the barrel, and that length gives the powder more time to act against the bullet.

Anyway, there's the outcome. I was happy to see that the little guns still are packing a pretty good punch.

How did the felt recoil compare?

The lightweight small revolvers I've fired had surprisingly sharp recoil for the power they produced. The 940 is a heavier all steel gun than the light, J-frame 38s I have fired but I would still expect more felt recoil than a semiauto would produce, even a small and light one like the PM9.

Good info.

It also shows how much 9mm out of a 2 inch revolver (1151 fps) is running close to .357 mag velocities without the blast or recoil.

I've clocked Remington Golden Saber .38 spl. +P out of a 2 inch, and it runs around 860 fps. As Paul Harrell would say "291 fps is a lot more".

And why S&W needs to re-release the 940 or a scandium 9mm J frame.

In the meantime, I've got my Ruger LCRx in 9mm.

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Watch & Pray

The recoil of the 940 is sharper than the PM9, likely because of the location of the firing hand relative to the bore axis.

I bought the 940 within the last 18 months for exactly the point you make about the .357. I wanted a J-Frame pocket gun, but didn't want to deal with the blast of the .357. I felt that the 940 would be a great compromise, better than .38 +P but less blast than .357. It turns out that this is true.

The only downside is the weight. It's definitely much heavier than the PM9. I could definitely see an argument for S&W to bring out a lightweight J-Frame in 9mm. If they can do it in .357, the 9mm pressures are less.

The difficulty with that path is that the 940 is already not much fun to shoot. I find mine to be worse than my 296 with Gold Dot JHP. I suspect a lighter version might be really unpleasant.

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NHI, 10-8.

Just want to throw this out. From what I understand and have found in researching the 9mm HST's the standard velocity is actually a slightly better performer than the +P out of a 2" - 3.5" tube. That is because the +P version travels about 60 fps faster and expands faster. The more rapid expansion leads to less penetration. While the +P does expand ever so slightly more (not really enough to matter) I'd rather have the extra 2-3 inches of penetration with the ever so lightly less expansion.

I am splitting hairs and both the standard velocity and +P version of the 124 grain Federal HST are IMO the best of the best, why not get the very best out of a short barrel.

There is a Youtuber (Ammo Quest) who does a superb job in explaining and actually demonstration this if you are interested.

Interesting point. And ties in nicely with some of the ".38 ammo" threads running around here.

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Because of the metric system?

I'm pretty sure I have exceeded that velocity with the 124 gr. Gold Dot and Power Pistol in my 2" 940. Extraction was fine and there was a point of diminishing return where more powder did not produce any more velocity. And yes, the recoil is quite sharp. Even lesser loads have a pronounced recoil. I have shot this revolver at 100 yards and was surprised by both the accuracy and the fact that the windage was right on. I don't think that the modern S&W is capable of manufacturing a new 940 that is as nice as the old ones.

This is great to know. I have 2 pocket 9s. A KelTec P-11 and Taurus G2c in .40 with a spare 9mm barrel. And my 6906.

Yes, the P-11 and the G2c seem ghetto, but the P-11 takes all my S&W double stack 9 magazines, and my G2c takes all my double stack Sig P226/229 magazines. (And the newer G3/G4 series also use Glock sights)

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NRA RSO

The Federal HST is a favorite loading. My guns have 3.6" barrels so I get an extra boost.

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"He was kinda funny lookin'"

Thanks for taking the time and doing the work!