Displacement / Time = Velocity

I spent a few minutes this afternoon setting up my chronograph so I could quantify the difference between the two loads I currently have.

chrono1

The normal spot where I shoot is overgrown right now, so I set up to shoot at a low angle across the creek.

chrono2

As a control, I shot 10 rounds of Remington UMC. It ranged from 976 to 1023 fps, averaging 1002 fps, for a muzzle energy (and thus, recoil energy) of 401 ft-lbs.

The 4.4 grain Power Pistol loads, the ones that don’t run the gun well, were, not surprisingly, significantly slower. They ranged from 677 to 743 fps, averaging 705 fps, energy 199 ft-lbs. Interestingly enough, the first shot was the lowest speed and it was the only one that didn’t cycle the pistol, but several of the empties literally rolled off my knuckles on ejection.

For the 5.5 grain loads, I shot 15 rounds instead of 10, partly because I wanted to give it more chance to fail to eject. The velocities ranged from 838 to 899 fps, averaging 869 fps, energy 302 ft-pounds. That is an energy increase of 50% over the 4.4 grain. They were definitely a little sharper, but more importantly, they worked the pistol really well.

I will split the difference in a future load, seeking the balance. In the mean time, I have a stack ready for the class.

ammostack

While cleaning the pistol for the class tomorrow, I finally found and solved the issue where my magazines would rarely, if ever, drop free without being manually pulled out. I kept examining the magazines themselves, but it turns out to have been a roll/burr in the magazine well on the pistol itself. I neglected to take before pictures, but here is the repaired well.

magwell

All magazines I have drop freely now, so I can put the stock floor plates back on them, presuming I can find them. The big plates didn’t help anyway.

magazines

 

 

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