I don't know if you know this or not but you can use one of the plug screws from the scope base holes to fill the front sight hole. Thought it was worth mentioning.As others have posted, Ruger MKIII's come with included rails, and are pre-drilled and tapped. Here's one very heavy example. (Heavy doesn't matter much when your shooting from a rest.) It'll hit a fly in the eye at 25 yards.
I was deciding between the Ruger MkIII and the Buckmark. The Ruger had the rail included in the box, the Buckmark did not, I'd have had to order one from Browning.
As others have posted, Ruger MKIII's come with included rails, and are pre-drilled and tapped.