Hey Mike, that block of yours gives me an idea. With just a little more work you could turn that into a loading tray of sorts, or at least add to it so that it helps guide a pellet to the bore, especially if you are prone to drop it at the last instant. If you get it right, you almost wouldn't have to look to see where to load the pellet. (If you look at my list of guns, you'll see I don't have one that could use it, but I could see it making the job of loading a little more sure in addition to the added safety.)
Regarding mole idea. You can find/buy pellet tubes that will feed a pellet into the breech. They sort of look like ball point pens. The clicker helps you push a pellet into the chamber. Keeps fingers clear at the same time. It will work on breakbarrels but not on fixed barrels like the 300. I haven't found anything better than issued fingers for that. I tried too! That was before I found a short scope that let me get my fingers into the chamber area. I don't think we need to obsess on the subject. The nasty wound shown was the result of a slip and failure in process not pulling the trigger. Many have done well with the usual care that one should take.
I never could use a pellet pen. No control.Have a close look at the QB-57. That's how they all should be. Notice the safety catch at the breech.
Bill I am really trying to wrap my head around how this QB-57 would differ from my FWB300S
Hmm. Interesting tool. Have you considered that you could adjust the length of that screw to make it double as a pellet seater?