|Remington 870 Conversion Kit|
I have a Saiga and I love that.
I saw this conversion kit for a Remington 870 that switched it from tube to magazine. They also have kits for Mossberg 500 series.
It accepts standard Saiga mags, even the big drum mags.
The cost for the kit is $499.
--Might be a fun project in the future. I have a lot of other things I need to spend $500 on though.