Edit: I've just had a look at the Rowen single shot loader and been told about your particular dexterity problems.. my loading tray probably won't help at all then, it's a tray rather than a loader.
If you look inside the block you'll see that the hole for the probe is larger than the probe. What you could do is glue a bit of rubber inside the block at the front with a hole in it just large enough for the probe but not large enough to allow a pellet to pass back through.
The other solution is to remember to always point the barrel down when loading your gun.
Last edited by Brian.Samson; 14th July 2013 at 09:04 PM.