WB
Loving your gun from the inside out.
Monday, September 28, 2020, 20:14

I’ve been enjoying learning the FN HP 9mm pistole. Only passingly a John Browning design, honestly. It feels fantastic in the hand, just the right amount of heft, great pointing. The safety is horrible, all mushy with no telling detent, no feel at all. One issue I have is how to carry it loaded. The 1911 cocked and locked seems most reasonable, but that mushy safety does not instill much confidence. Hammer down is ok and safe, being a rebound type firing pin. But one must then thumb back the hammer to shoot.

One fascinating design element is the overhead “teeter-totter” style sear bar that interfaces the trigger pin and sear pad to trip and drop the hammer. The hammer spring is quite unique itself but not germane to the topic. It can create its own issues.

My gun was having mis-fires. The hammer was stopping at the safety notch, not dropping completely. It was intermittent and very disturbing. It manifested itself only after I cleaned the gun. What could I have done?! All I did was dig grime out of it. Everything checked out, over and over again. I was drawn to the sear bar and the two points that worked with it. Pulling the trigger pushes the trigger pin up (I long ago removed the magazine dis-connect parts), that action pushes the sear bar up on one end, pivoting down on the other, the sear pad contact pushes the sear down to release the hammer. Seemingly debris could get under the bar and make it not move as it should. Plausible since it’s in a groove on the underside of the slide. I’d sure not want to over lube it and invite grime. I finally decided to true the surfaces of the trigger lifter and sear pad. I noted the surfaces did indeed have pitting and were uneven. The bar itself is very crude looking and rife with tool marks. All this needs to be taken apart and polished. The roll pin in the slide seems to hold it in place. No doubt a custom would have had all these details attended to. My truing and polishing of the two interfacing pads were rewarded with a complete end to the hammer/sear malfunction. I found it. More work to be done but it’s satisfying to identify an issue and understand the inner workings much more intimately. It endures the gun much more to me.

The sear pad surface under magnification. Sanded smoother but still not flat. It may require some careful light stoning to restore. There is a pit in the center. Perhaps I removed all the grime out of it causing a poor interface? It's now better but not totally right.

The trigger bar/pin. Still not quite perfect.

You can see where the trigger pin has been pushing on the sear bar. A polish would only help.

The sear bar contact point, only under magnification, I can see it's a terrible inconsistent surface. This will bug me until I can remedy. But at least it works.