i was wondering if anybody knows where i can find a magazine extension for a mossberg 500 20ga, iv looked all over the internet and cant find any for the mossberg (i found one for an 870 remington 20ga)
The design of the 500 will keep you from adding any kind of extension. A few companies make high capacity kits for 12g that replace the entire mag tube and barrel, but I've never seen one for a 20g.
Try calling Mossberg if you cant find it. I'm sure they can come up with one. (800) 363-3555. Theres the customer service/parts number. It just unscrews from the receiver and I see the shorter barrels at flea markets cheap all the time. You just have to know what your looking at when you go.