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mmattockx

mmattockx

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I have a bubba'd Mauser 98 with a straight bolt handle. I would like to mount a scope on it, but that won't fit with the handle. Is there any great reason I cannot use a small welding tip on an oxy/acetylene torch and simply do my own bent bolt handle?

Before people go nuts about the safety and all, I am a mechanical engineer and understand better than most what I am doing to the steel. The handle has no great strength requirements, it simply has to #### the firing pin spring on opening and be strong enough to open/close the bolt. The lugs do the work of keeping things together under firing pressures. Heat will be very localized on the handle and it will be done quickly.

Is there anything I am missing, any reason not to do it my way?

Thanks,
Mark
 
thousands of handles have been bent that way on 98's 96's etc. Heat sink for the threads is sometimes used when you want to weld another handle on, but lots of them are put on with TIG and no sink.
 
Randy B said:
thousands of handles have been bent that way on 98's 96's etc. Heat sink for the threads is sometimes used when you want to weld another handle on, but lots of them are put on with TIG and no sink.
Click to expand...

I am not cutting or welding anything, simply heating the existing straight handle and bending it to look like a K98's.

The threads in question are the internal ones that hold the bolt together? I expect the barrel of the bolt to barely get hot, as I will be heating the small bolt handle in one very local spot only.

Thanks for the input,
Mark
 
The guys are talking around some form of heat sink. A small, hot, carefully aimed flame isn't going to radically retemper the whole receiver. I would think that closing the bolt in the action will give you a clear idea of where on the shank to heat and how far to bend. The mass of the receiver will help dissipate more heat than just cinching the bolt in a vise.
 
maple_leaf_eh said:
The guys are talking around some form of heat sink. A small, hot, carefully aimed flame isn't going to radically retemper the whole receiver. I would think that closing the bolt in the action will give you a clear idea of where on the shank to heat and how far to bend. The mass of the receiver will help dissipate more heat than just cinching the bolt in a vise.
Click to expand...

For some reason, the idea of doing it in the receiver made me twitch. No reason, it just did. Fair point on the heat sink effect, I will look at the receiver and see if that seems like a reasonable thing to do.

Thanks,
Mark
 
If you look at the root of the bolt handle, down near the bolt body, there is a beveled section that engages a matching bevel in the receiver and generates a camming effect to pull the cartridge out of the chamber. That cam is case hardened to prevent wear.
You will need to check that bevel on the bolt handle after welding and reharden if it is not glass hard. A file should not touch it. Other than that and keeping the locking lugs cool there is no other issues.Good to go.
 
I missed the comments about welding in the receiver when I did my earlier posting. The receiver surfaces that the bolt slide on are obviously hardened as well so I would not do that my self. Wrap the lugs with a wet rag and keep checking and keep the rag wet.
Another possibility would be to freeze a block of ice around the lugs and say up a inch or so. I never tried that but it would seem like it would work.
 
alinalberta said:
I missed the comments about welding in the receiver when I did my earlier posting. The receiver surfaces that the bolt slide on are obviously hardened as well so I would not do that my self. Wrap the lugs with a wet rag and keep checking and keep the rag wet.
Another possibility would be to freeze a block of ice around the lugs and say up a inch or so. I never tried that but it would seem like it would work.
Click to expand...

No welding, simply heating the slender part of the bolt handle with a torch and then bending it. The bolt body should not get anywhere near hot enough for long enough to affect any heat treatment that was done. The locking lugs are at the far end of the bolt from the handle and will not even get beyond warm to the touch. The handle is so small that it should get red in only a few seconds of heat, then it gets bent and left to cool. Nothing at all like the heat input involved in arc welding.

Edit - I went and had a look and I see the hardened surface you are talking about. It will definitely get hot, as it's right beside the area that needs to be heated. Hopefully, it will not get pooched in the process. I think I need to do it out of the receiver, too. There isn't enough clearance to get heat right where I want it without also hitting the receiver and I don't want to take the chance on affecting it.


Mark
 
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You will end up with a bolt handle that is short, but works. Clamp body in a vise,heat it while dripping water on a heat sink/plug stuck in the end. Not the best method, but it works. Better to cut the square root about 3/8" from the body, about 3/4 of the way thru, heat it, bend down, then fill the opening with a tig. Leaves a bit more length, and a straight handle. You should try to keep the camming surface from getting real hot (dull red) If it gets soft it may gall when opening/closing the bolt. Good luck, Mark
 
FWIW why not just do it right, it seems that you are in spite of yourself going to invest a few bucks in this "project". Get / make a heat sink for the threads etc., cut the handle about 1/2 inch out from the bolt body - you can use the outer edge of the receiver as a guide - and buy a handle from Brownells / reverse your own and tig weld it on the receiver stub, smooth & polish etc. I don't think just bending unless its extreme will give you the clearance you are needing. --- John 303.
 
mmattockx said:
No welding, simply heating the slender part of the bolt handle with a torch and then bending it....Mark
Click to expand...

Heating and bending will put more heat on the bolt body than cutting and tig welding. Plan on using a heat sink if you are going to torch it. Brownells sells them or use a home made one like the the wet cloth. Engineers are especially prone to Bubbaizing because they think they know and don't listen to experience...

There's a vid on youtube by Midway, shows how to cut and weld a bolt handle. It's easy.
 
When a handle is altered for scope, there is often a forging process used, involving forming blocks, and a threaded insert into the bolt, to protect the threads. Fast to do with the correct tools.
Bending a handle so that it is like a K98k will allow it to clear a very high mounted scope, or one in a see through mount. For a low mounted scope, just bending the handle won't work. It is sometimes necessary to cut the receiver to clear a low turned handle.
I really doubt that you will be able to get the root of the handle hot enough to bend it easily without affecting the cocking cam. Using a small tip, you might have to cook the handle before it gets hot enough to alter.
Making a partial cut, bending the handle using the unfinished part of the cut as a hinge, (bend at red heat) and then filling the notch makes a better job than just heating and bending.
Cutting the handle off, and welding on a replacement can produce the nicest conversion. A jig is needed to hold the new handle in place while welding.
Keep in mind that the root of the bolt handle provides the primary extraction camming.
To do any of the conversions involving welding heat requires an appropriate level of skill. A bolt can be ruined quite easily.
Brownells sells welding rods which result in a very nice job.
In addition to the handle alteration, the safety will need attention, and mounting holes will have to be drilled and tapped.
 
Don't woory about wet rags, dripping water, swamp mud or any of these things. clamp the bolt in the vice. I have welded a whole bunch of mauser handles and have never had the bolt head get hot enough that I couldn't pick it up bare handed. Do screw in a plug to maintain the form of the thread. You can heat and bend but it is preferable to cut partially through, as 358 has stated, then weld in the resultant notch after bending. You can weld it with oxy-acetylene. The bolt will work better if you re-harden the cocking cam. Regards, Bill
 
Leeper said:
Don't woory about wet rags, dripping water, swamp mud or any of these things. clamp the bolt in the vice. I have welded a whole bunch of mauser handles and have never had the bolt head get hot enough that I couldn't pick it up bare handed. Do screw in a plug to maintain the form of the thread. You can heat and bend but it is preferable to cut partially through, as 358 has stated, then weld in the resultant notch after bending. You can weld it with oxy-acetylene. The bolt will work better if you re-harden the cocking cam. Regards, Bill
Click to expand...

I like the cut and bend idea better after looking at it more closely last night. Where I need to heat to get the bend I want will get right into the hardened cam area. I can cut it close there and get a sharp angle bend easily with a bit of heat, then get a friend to touch up the notch.

As noted, I also need to sort the safety and drill and tap for scope mounts. The safety will be taken care of with a Timney trigger group and the drilling and tapping is no real problem with the bolt handle out of the way.

Thanks for all the helpful responses,
Mark
 
I've done this. Cut the handle and reweld. You will get a tighter bend, more precise repositioning, and possibly wish to lengthen it or replace it in the process. I'd wrap a damp rag around the bolt body to keep it cool. If you just heat and bend a solid mass, you get great displacement of the metal to make a tight bend as it folds. It will look like someone bent a piece of clay, as it narrows in one dimension and squashes outward, displaced by the bend. If you make the bend really gradual, it will make the handle annoyingly short in my opinion.
 
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