I had a speedbead on my 870. I turkey hunted with it last year and everytime i shot i would always have my head as far back on the stock as possible and it wasnt very comfortable. I was shooting 3.5" mag blends and i didnt want to get slapped in the face. Needless to say i switched to a 336 mount for this year. If you were only clay and wing shooting the speedbead would be awesome, but i had the protector on mine and i was always nervous it was gonna hit me. Everytime i shot a turkey last year i found myself worried more about getting hit in the face then i did on focusing on the actual shot, so for that reason i went with the 336 mount. Now i can shoot in comfort. You can get a weaver rail and picatinny mounts will fit it. Weaver makes a one piece and two piece rail you can get for your 1187. The two piece will give you a cleaner look, but you would only be using one of the two mounts. You could also use the 336 mount as I did. Its just up to you what you think looks or would work better for your situation. If your handy you can drill and tap your receiver yourself. I did mine myself and it was easy just take your time and measure correctly and you should be fine. You will need to have a drill press handy though.
