What caused this?

[huntincowboy]

Hey everyone! I was starting to work up some standard pressure loads using green dot and 300 gr bullets for 45 colt. Well a bullet got stuck and I was getting ready to tap it out and I found this http://img.tapatalk.com/d/13/11/18/tutereza.jpg

I have never noticed it, but honestly I never look there I just wipe it down without thinking. It doesn't look right to me, but I don't know what is. It's behind the cylinder on the top strap. I have shot "ruger only" loads before in this gun. It looks like it is rough, so I don't think it was drilled. Any ideas? I wouldn't think there could be flame cutting there but I'm no expert

[Lonegun1894]

I just checked on mine, and that is the hole that the elevation adjustment screw is in. Looking at your photo, your sight is set pretty high, meaning your screw is backed out quite a bit, leaving the hole more exposed, and if I had to guess, since you say you just wipe it without paying much attention to it, you have fouling collecting in the hole. If you clean it out, you should see threads--and also be able to lower your rear sight should you need to if you change loads some day.

[C. Latch]

My SS Bisley has the same dimple. I'm thinking it's just a product of the casting process.

http://i78.photobucket.com/albums/j85/clatch/Mobile%20Uploads/19efce2c-dfac-4583-92b9-d2f90f6382bf_zps4645f37f.jpg (http://s78.photobucket.com/user/clatch/media/Mobile%20Uploads/19efce2c-dfac-4583-92b9-d2f90f6382bf_zps4645f37f.jpg.html)

[RED333]

Yep, just checked my BlackHawk, same spot.
Your pistol is broke, send it to me for testing.:kidding:

[huntincowboy]

Haha thanks guys! Not sure why I never noticed it :/

[MtGun44]

Rear sight screw hole.

Bill