Borderboss
Member
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.
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.


