If that is attached to the receiver, is the receiver solidly connected to the barrel? Some are. Most aren't. Cantilever barrel for scopes. Red dots go on the barrel. And be consistent with how tight the barrel is screwed to the magazine.
Thank you all. This is for my remmy 11-87.
thanks for all the replies.
my gunsmith said he can drill and tap my receiver to take a picatinny rail system. i am going to go this route.
no clue! at all.You doing a full rail?