Do I need to get my 870 drilled and tapped and then what base or mounting do I need to get it set up
If you do not want to drill and tap you can put a b square mount on it.
I'm am having my 11-87 drilled and tapped now. I will be putting a vortex venom on. Gunsmith is putting a Weaver rail. Vortex includes a picatinny with the red dot. So whatever route you go if it's a Weaver style rail contact Vortex and you just ship the picatinny mount to them and they will send a Weaver back.
I also want to put one on my sx3 longbeard that has the cantilever. Do I need anything other than what ships with venom to mount to cantilever.
The Vortex will fit the same mounting system as the Burris FF's. I have 2 with the 336 mount/base which is the lowest you can go. I see where Sumtoy is building a new base that looks really nice. The Vortex will also accept the Burris protector which is not a must have but I like them.
Ridge Rooster