Question on welding bad scope holes shut.

I have read on this forum and others about welding bad scope holes shut to redrill or hide. I have an old .22 that needs that done to it. My question is . Is there anything I would do different because of it being a receiver? Should I just weld the holes over and clean them up? I'm a mechanic and have been welding for many years so I know what I'm doing on a piece of metal I just have never done anything like this on a rifle. I'm thinking just to back the hole up with a piece of copper and mig them over and go from there as far as finish. Would this be correct?

If you decide to plug weld the holes DO NOT use copper as a backing plate, it will cause cracks in the weld. Use yellow brass or ceramic.

We used wire feed weld to fill holes from screws. A bit of dremel and polishing and they mostly took blue like any other part. Sometimes you have a dark spot. Don't worry about metallurgy. It won't change enough to worry about.

Thanks for the info guys. I will probably eventually try it I just have to add it to the to do list.

FWIW, if you do this in the vicinity of the locking lug recesses, you might want to devise an aluminum or copper heat synch and invest in some thermal paste to draw the weld heat away from the hardened locking surfaces.

drill your new holes before you weld up the old ones..

I wasn't going to put another scope on it just an open sight. Why (out of curiosity) would I drill the new ones first? Is it just so there are no problems drilling if the holes aren't welded perfectly closed? Wouldn't the brass backing up the hole pull the heat away fast enough?

This link is to a video about tig welding old scope holes.http://www.youtube.com/watch?v=WShQMnUEA9g
There is also a video by Larry potterfield at Midway about plugging with screws.

I think the reason Chuck advised on D/T ing new holes first is because metals react differently to the application of heat. Some will become softer in and around the weld area and others will become so hard as to be next to impossible to D/T holes. There are carbide tools out there to drill into the hardest of metals but to the best of my knowledge the taps to thread them with don't exist, especially in 6-48 and 8-40 sizes common only to the gun industry. One thing to add to Chuck's recommendation is after tapping the new holes run anti-sieze coated screws in to avoid distortion during welding, especially if the hole(s) to be plugged are relatively close to the new one(s).

its next to impossible to drill and tap a welded area, it seems to suck all that crabon right into that spot...iv had a few frustrating jobs...so i learned, drill the new holes, then fill the old ones.