Been looking into doing a 10round or so spring fed tube magazine mod to an old spyder I have. I've found a nice looking conversion that seems to be pretty popular, but I can't find any info on it really. Looks to be maybe parts from another gun rather than a conversion, but I am not sure. I've been searching, but I think I am using the wrong terminology as I'm not really bringing anything up.
Here's a pic and also a link to someone doing the conversion on a cocker. (unfortunately, he doesn't say what the magazine came off of)