I have 2 identical in apperance Mossberg 22 rifles. The only diffrence is that one has the number S46M and the other says 46M-B Does anybody know what that means. I am also looking for a Weaver scope mount to mount a bigger scope on one of them. It has one of those old original little scopes on it. Its a weaver but it is old does not bring in alot of light and its a little hazzy. Its the way my Great GrandFather gave it to me. I would like to modernize it a little. And are these guns good guns? Thabks for your responses.