I know that this is not an answer to your question but I had an old Mosin laying around and decided to put a side mount on it. I used a Weaver 1" detachable side mount base and left the rifle in its original form, straight bolt and all. In drilling, I started with a small bit first and worked up to the proper size bit for the holes, this old action had a pretty hard surface and was a little hard to drill, that is the reason for starting with a small bit. Used an old bushnell with a long tube and had to remove the front sight due to the front bell of the scope. Had to place the scope as far forward as I could and still get eye relief and to facilitate loadiing. When you lift the bolt and pull it all the way back it just clears the eye piece. I did this just to see if it was possible and while FAR from the best system it worked.
