After heating with a carburizing OA flame to cherry red, do you quench in water or oil or not at all. Do you maintain the cam surface in the acetylene feather or at the end of it. Anybody have a good link explaining it. Thanks.

Hold the bolt vertically with the cam up, this keeps the heat in the desired area as heat likes to travel upward mostly.
Get the heat in fairly quickly.
Quench in water and you are good to go.

I can’t remember where I heard it (either a Jack Belke post of an old gun smith I was talking to a while ago), but I picked up from somewhere that BRNO bolts had a higher carbon content so should be oil quenched and German bolts needed water. I can’t substantiate this, and metal knows more than me on the subject. However, quenching in oil is safer if the carbon content is higher than about 0.7% - which id highly doubt it would be anywhere near that high anyway so maybe there’s nothing in it. Going in hard and fast is the go - get just the area to harden cherry red and into the quench all in the shortest space of time. Use the edge of the inner blue flame.

Metal I think I recall in out last conversation you said to leave it full hardness and not temper?

Sorry to slightly hijack kda55 but I feel my next question is also relevant: I finally managed to weld my homemade bolt handle on last week and somehow managed to stop any heat (at least - no straw colour) reaching the cocking cam by cooling the root and cam area with the compressor blow gun after each pass with the MIG. While cleaning it up (which I’m still going on) I’ve found the extractor came (very root at the bolt body) is still hard - as in a sharp file skates off it. I guess the combo of the cool bolt body (what is this phenomenon called?) and blown air quenched the weld area fast enough to harden it. So I’m planning on not heat treating any of it - how does that sound?

Note - I’m very far from a pro. This is my rifle, and I’ve only done two handles before. I know enough to be dangerous



I used the Jack Belke method of getting a full pen weld

Thank you.

Just a suggestion, but generlly when replacing a bolt handle the goal is to make it scope friendly so that ultra high rings aren't needed.

This handle was designed for a rifle primarily designed for open sights but the owner wanted the ability to mount a scope and use rings no higher than mediums. This handle met both criteria:



You may want to move your handle in closer to the bolt body so as not to end up with a 1/2" long root.

quote:

Originally posted by z1r:
Just a suggestion, but henerlly when replacing a bolt handle the goal is to make it scope friendly so that ultra high rings aren't needed.

This handle was designed for a rifle primarily designed for open sights but the owner wanted the ability to mount a scope and use rings no higher than mediums.

You may want to move your handle in closer to the bolt body so as not to end up with a 1/2" long root.

That’s a beautifully done handle, looks perfect. I’m not sure if you were addressing me or the OP - I did consider moving it in closer but this rifle won’t even be d&t for scope bases and I’m trying to stay reasonably faithful to an original Mauser sport so didn’t want to notch the receiver too much. Also, I find cleaning up of a really close root tricky. As it is I brought it in a little, and if one of my kids wants to scope it after I have no say in the matter it can be hollow ground for a low scope and still Leave enough handle left I reckon

quote:

Originally posted by z1r:
Just a suggestion, but generlly when replacing a bolt handle the goal is to make it scope friendly so that ultra high rings aren't needed.

This handle was designed for a rifle primarily designed for open sights but the owner wanted the ability to mount a scope and use rings no higher than mediums. This handle met both criteria:



You may want to move your handle in closer to the bolt body so as not to end up with a 1/2" long root.

That is beautiful work!

On a Brno mod 21 or 22, the original bolt is strictly for irons, but can be heated and cut or hammered for a scope and looks very nice and works for scope or irons, or a newly install bolt should be positioned welded to clear a low mounted scope. I have a number of Brnos done by Jack Belk, and they work for both ie
irons or about any scope...BTW they were tig welded..Never a problem over the years.