Drilling Barrel

[sparkie]

I built a rear sight for my Pedersoli .50 cal(Blue Ridge) rifle is 6" long so that I can get the rear sight closer to my eyes.I need to drill and tap a hole so that I can take the side to side movement out of the sight. The wall thickness of the barrel is .200". I was thinking of using an 8-32 screw. How deep can I go and still be safe?

 

[gmww]

I'd use the dove tail depth as a guide if that would work. You can just measure how deep they put the dovetail.

 

[flintriflesmith]

A finer thread would probably be better. More threads in the same depth hole. That is why modern rifles use 48 threads to the inch screws for sights.

 

[jerrywh]

A small round hole is perfectly safe at almost any depth in a muzzle loading rifle. Just don't go into the bore. I would use a #6-40 as apposed to a 8-32 .
At a chamber pressure of 12000 psi the pressure on a #6 screw is only about 200 lbs. You will never blow it out and it has a negligible effect on the barrel strength. you need the fine threads on a short hole. Pedersoli barrels are made of tough steel. It wouldn't worry me in the least.