My first ever gun repair, welding SKS reciever. With pics.

[Exposure]

I have recently been bitten by the C&R bug and have fallen in love with SKS's. One of the ones I bought was pretty rough with a trashed stock, and no finish. It functioned great but looked like hell. I thought it would be fun to make it into a "sniper" SKS so I got a Dragunov stock, muzzle brake, a couple of colors of Duracoat and a Choate scope mount and scope.

Well long story short when I drilled the four holes for the scope mount I screwed up on one, I can't imagine how the heck I did it but I got one of the holes in the wrong place. To make matters worse I didn't like the mounted position of the scope feeling it should be a little further back. So I set the gun in the corner and felt pretty darn bad about it for the last couple of weeks. Yesterday I decided I was going to do something about and started practicing with my Lincoln MIG welder filling and grinding holes in a bunch of scrap steel I had laying around. Today I felt I was ready to go and the pics below tell the story!

Here is the pic of the original holes. The third hole on the right is the obvious culprit. UUUUGGGGGHHHHH!!! Was how I felt when I wiped away the oil and shavings and saw what I had done. I considered buying another SKS and starting from scratch.



Here are the holes welded up and ready to be cleaned. Hope I do it right!



And the finished product. I used very low heat, just enough to penetrate, and very short dwell time on each bit of weld I added. I hope this kept any damage from occuring to the reciever itself. It all is still perfectly square and the action cycles fine. I am assuming it is okay. Once I Duracoat everything there will be no evidence externally of any repair. Of course it will be covered up by the scope mount anyway which will be about 1/2 inch further back, AND drilled properly!



I think it came out pretty good for a first timer. Now I just need to redrill and finish off this darn project! Full pics will follow when it is finally put together.

 

[BluesBear]

Good looking work!

 

[Exposure]

Thanks Bluesbear!

I love working with metal but have never dared do much with my firearms. Since this one was so cheap I figured what do I have to lose.

Just as an aside here, the steel that the reciever is made of was ridiculously easy to drill when I did the original hack job. It seemed amazingly soft for being the portion of the weapon that takes the most beating. I had purchased two drill bits and two taps in anticipation of a hard time drilling and tapping those holes. I wonder if all SKS's were like this? This particular gun has obviously seen a lot of use yet the reciever seems none the worse for the wear.

Anyway, just thought it was interesting. Especially in light of the cast vs. milled vs. forged by the hand of God, etc. etc. etc. type arguments that seem to come up on occasion. I thought a nice piece of milled steel like this was going to be a bear to drill through.

 

[redneck]

Guns aren't really made with THAT hard of a steel, not too surprising that you could drill it so easily. You can actually buy 4140 steel prehardened for gunsmithing stuff, because its still easily machined at the hardness guns are made at.

 

[scott.cr]

Nice post!

I have done this exact repair before: I was making a DIY "SVT scope mount" for the 59/66 and forgot to lock down the head on the mini mill and ended up buggering a hole.

I was afraid of warping so I heated the receiver in the oven to 350 degrees to minimize thermal variation between the part being welded and the rest of of the receiver. Then I backed the holes with a copper bar and proceeded to MIG weld.

In hindsight I should have clamped the copper in place, THEN put in the oven, to minimize the time from oven removal to welding.

The copper bar makes a positive backing to your hole so you don't have weld drip-through, and the weld won't stick to the copper. (BTW this is called plug welding.)

Actually I didn't even have to file it and it would have looked fine!

 

[Exposure]

Hey Scott!

That is a fantastic idea! Thanks a lot. The holes on the inside of the reciever are visible. While nothing dripped it is obvious that something was done there. The copper bar is an outstanding suggestion.

I didn't preheat the reciever before welding though. Is it possible I did any damage? If there is any warping the square doesn't show it, but could I have softened the steel or anything like that?

 

[scott.cr]

I don't know that the SKS receiver is fully heat-treated when it is made. If it is, then the portion that was welded is probably annealed (softest state).

However, if there is nothing wearing against that portion of the receiver the effect is minimized. If everything checks out square with your gauges and functioning hasn't changed I wouldn't worry about warpage.

I'm not explicitly familar with the type of stress the welded portion of the receiver sees, but if it really gives you the heebs you can keep an eye on it and discard once cracks start to form. Would I worry about it personally? No. Even some of the AK receivers are only spot heat treated where the pins go through, and they're cheap stamped steel.