Thread: Would this fit my 870?

Most shotguns are threaded internally to fit chokes. The saiga is threaded externally. So you will need to have the barrel threaded to suit.
It may involved shortening the barrel to get enough thickness of steel. If yours has removeable chokes. Talk to your gun Smith.
Cutting the chokes out will make it only short range. As the pattern will spread very quickly with no choke anymore.
Also a break will make the firearm much louder. Especially a short barreled one. It could mean plugs and muffs only to shoot it. Not ideal for hunting.
Just things to consider
Greg