It's an old trick for cheap watches: thing stops running, you take the back off and lay it in a saucer of lighter fluid, move it around a little. (Don't try this with an modern watch! ETA: or most older ones, see Sevasteen in Comments.) The volatile petroleum distillate washes out the gunky old oil, dust, etc. Advanced practitioners would add a drop of sewing machine oil.
My balky Iver Johnson top-breaks got a version of that prior to going to the range Sunady afternoon: several drops of Ronson fuel down each side of the hammer. I worked the action (controlling the hammer!) multiple times and then followed with some proper oil ("FP-10," I think) and some more working. The older one, with a stiff hinge, got the same treatment there.
And what do you know -- it worked! Both worked much better today. They could still use a professional going-over but in the case of the Supershot, it made a huge improvement.
I shot my High Standard Sentinel, too, and the H&R 623 just 'cos it is so darned much fun. I saw -- and should have photographed -- an immaculate 622, the blued version; this one had a 6" barrel, a nice holster and cartridge belt (for .22s!) and a story: an elderly gentleman drove up and asked Guy (the range boss; also, he practices law) if he could drop off a gun he no longer wanted. ("My business partner convinced me to buy it a long, long time ago and it just makes me nervous to still have it around.") This was a bit of a surprise. Even after Guy pointed out he could instead take it to a gun store and turn it into money, the man was sure he wanted to give it away there and then. He just wasn't comfortable having it. Evidently, his story was found plausible, and when the firearm in question was revealed, there it was: a little pull-pin .22, a back-yard can-plinker. Naturally, the rangemasters didn't want to see it go unwanted... (I've shot it. It needs cleaned, lubed and maybe a new mainspring, but it's almost 100%). Made sometime between 1968 and 1970, depending on who you believe about H&R date-coding.
With my guns, I got off to a lousy start but found the center soon enough. The Sentinel is a particular treat; once I have got my head in the game, it's a magic fun machine, "Boom! in the black. Boom! In the black," over and over.
CARBON MICROPHONE CHECKING
4 weeks ago