870 dm magazine question

[1911vm870]

I have looked all over the internet and just cannot find . are there mags out that are more than 6 rounds. that is the only reason i have not gotten one yet. thanks

[Scorpion8]

I see 6-rounds as the max. Lots of talk about feed issues since shotgun shell rims extend beyond the case diameter like a rimmed cartridge.

[Romulus]

I wonder if the talk applies to old time mag fed shotguns like Atis Armi, Saiga, Franchi, etc, or is it just the 870 DM?