Has anyone tried one of these? Looks kinda chincy, but it might be something fun and new to try. Who knows.
I'm assuming you are addressing the M series, as the A1's already have a picatinny rail and that thing costs as much as rail mounted units. For the older M series, I suppose it would work if you couldn't find a rail adapter. I wouldn't expect it to hold any kind of zero for very long and it would be a range only toy. Personally, I'd save the money or spend it on ammo.