[BBBBill]

If you were going to weld up the stripper clip guide and thumb notch on a Mauser, what would you use for filler rod with TIG or gas? Would you use a block of a particular grade of steel to fil most of the space (maybe cut out of a similar damaged receiver) or just fill it with weld? Different choice for different vintage receivers (say early 1900s vs 1940s) or different for 96s vs 98s?

[rcmodel]

If I was to do it, I would grind off the clip slot, not fill it.

I would fill the thumb notch with a piece of pre-shaped steel, and weld it in with mild steel rod so the bluing would have some chance of matching later.

But I wouldn't do it.

On the 98 at least, the third or safety bolt-lug locking recess is in the rear ring.

And I would not want welding to mess up the heat treatment in that, or any other area of the receiver.

And there is always the possibility of heat warping the receiver by welding on one side of it and not the other.

rcmodel

[BBBBill]

RC, got it. Understand the risks. If I did it, I would use a heavy jig/heat sink to hold the receiver and lots of heat control paste.
You mentioned the 3rd lug on the 98. I have recently seen some of the BRNO commercial/military hybrid guns imported by EAA that were sold in the past couple years that were set up with the 3rd lug bearing. Obviously, they don't have the knowledgeable gunsmiths that they used to have.

[rcmodel]

that were set up with the 3rd lug bearing.Dang!

That ought to make getting good accuracy chancy at best.

rcmodel

[dirtyjim]

i'm assuming your trying to make a military action look like a commercial mauser action. when filling in the thumb cut its easier to file or mill the slot square then fit a metal plug to it instead of trying to fit one with a curved bottom. also mill some flat bar down to the exact size of the bolt raceway & clamp it inside the receiver. it will help line up the plug & give you something to clamp it to when welding. i've always had good luck using 1018 steel & the rods sold through brownells but i rust blue & it seems to be more forgiving than hot blue.
if your concerned about it affecting the heat treatment you can always sent it to blanchards to be recarburised, its not very expensive & i recomend it for any mauser project that your going to put alot of time & effort into

[frogomatic]

I'm with RC, it is, in general, a bad idea to weld on a reciever.

also, if the 3rd lug is bearing it's more of a saftey issue than an accuracy issue. If the saftey lug is bearing on the reciever, then it's likely that the locking lugs are not. A reciol impulse directed solely through the saftey lug often results in the lug shearing and the shooter having a bad day.

[BBBBill]

Frog, the safety lug comment was in reference to some new BRNO actions that were sold a couple years ago. They were visually pure military 98s, but sold as new. This is the same gun that Remington is now selling as a 798. On the ones that I looks over for a friend, the third lug was bearing. I confirmed that with measurements. Just a heads up for anyone looking at a Mauser of any vintage. Some folks don't know that is a no-go.