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Military Firearm Restoration Corner

Bolt Handle Replacement


Clemson

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Continuing the work on the M48 Mauser, I attacked the bolt handle. Let me state up front that I am not a welder. z1r does absolutely stunning Talley handles. I am pretty competent on the metal work other than welding..... One does what one does :rolleyes:

 

I chose a Brownells handle for this project. I like the style, and I have several on hand, so that is what I used. The Brownells handle comes as a casting. I actually did some polishing ahead of the welding just because it is easier to manipulate the handle before it is attached. This shows a Brownells handle as received and the one that I polished in preparation for installation:

BoltHandleWelding002.jpg

 

The tools needed to get started:

CuttingoffM98BoltHandle003.jpg

 

I use Dykem to mark the root of the original bolt handle:

CuttingoffM98BoltHandle005.jpg

 

Then I scribe a line to mark where the bolt handle crosses the receiver rail. I like to cut on this line. That will make for a minimal receiver notch but give me a handle that will clear a low-mounted scope. because this handle is flat on the back side, I can get away with a fairly long root.

CuttingoffM98BoltHandle006.jpg

 

The scribed line shows up well in the Dykem:

CuttingoffM98BoltHandle007.jpg

 

I cut the handle off with a hacksaw. If the bolt is too hard, you may have to use a cutoff blade in a Dremel or other such tool.

CuttingoffM98BoltHandle008.jpg

 

It looks like I left about 5/16" of stub:

CuttingoffM98BoltHandle009.jpg

 

Here is the new handle positioned for welding using a Midway welding jig and a Brownells heat sink:

BoltHandleWelding012.jpg

 

The last thing I do is smear Brownells heat stop paste into the cocking cam and install a copper "spatter shield" behind the weld area:

BoltHandleWelding014.jpg

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Now for the welding. Confession: I took the bolt in the jig to my friendly community college and got one of the welding instructors to TIG it using my rods. The rods are from Brownells, 3 1/2 % nickle steel. It is pretty much critical that you supply the rods. Given a choice, the welder will grab a stainless rod because the weld is less likely to exhibit porosity using stainless, particularly if the metal is not clean. The Stainless, unfortunately, will NOT blue, and you will be stuck with a funny-looking handle. Here is the bolt after it cooled off from the welding. I did buff off the welding residue and discoloration before I took the photo:

BoltHandleWelded006.jpg

 

I set the bolt up in the vise of my mill to hold it for filing. Yeah, I know that I could have used the mill for this, but I really like the control that I get from hand-filing the handle to shape. Can you guess what I used to guard the bolt body from stray file marks?

BoltHandleWelding005-1.jpg

 

Working away at the weld. This takes a few minutes:

BoltHandleWelding001-1.jpg

 

The "scallop" that clears the scope ocular requires a shaped grind. I use a wheel on my sanding belt for this contour.

BoltHandleWelding010.jpg

 

You really need to make this cut in pretty much one pass to insure that the surface is smooth.

BoltHandleWelding011.jpg

 

A bit of time on the buffer results in this. I used 140 grit followed by 320 grit.

BoltHandleWelding012-1.jpg

 

To insure receiver clearance, I used the Dykem again on the receiver and marked the place where the handle hits.

BoltHandleWelding014-1.jpg

 

It required just a few thousandths removal with a pillar file. This receiver is harder than woodpecker lips, so it took a bit of time to cut those few thousandths away.

BoltHandleWelding018.jpg

 

Finally, I reassembled the trigger and bolt assembly and tested the original safety to insure that I had not messed up the bolt alignment. Everything works like it should with minimal bolt handle jump upon firing. Success!

BoltHandleWelding020.jpg

 

Clemson

 

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Very nice work and a great tutorial.

 

Would it not have been better to take alittle more off the bolt then modify the receiver camming surfaces? The receiver was hard because it is case hardened. You likely cut through the case hardened surface.

 

Vlad

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Clemson,

 

Sorry about the hijack of the tread. Could you walk through the steps that you took on that action to the point it is in the pic? Where do you plan to go after that? More polishing? Send away for hardening? or has that already been done. It all looks so nice! and clean!

 

Thanks for the bolt demo too. Really good looking.

 

lc

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Very nice work and a great tutorial.

 

Would it not have been better to take alittle more off the bolt then modify the receiver camming surfaces? The receiver was hard because it is case hardened. You likely cut through the case hardened surface.

 

Vlad

 

Hello, Vlad. The notching is minimal, and it does not take place in a place where cutting through the case is a problem. As a rule, you can make the handle just so thin, and further thinning may affect the actual strength of the bolt handle. It is preferable to notch the receiver rail rather than reach that point with the handle. The Brownells handle is basically rectangular in cross section. Many bolts are round, and the shape of the notch is determined by the shape of the handle at the point where it meets the rail. I cut the root on this handle fairly long, and the notching required was very minor.

 

Clemson

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Clemson, from the pic it looks like you put dykem on the camming surface not the bottom of the rail. I think this is what vlad is referring to. Cutting the root of the handle instead of the receiver camming surface. Not cutting the bolt to avoid notching the bottom. Of course I could be wrong.

-Don

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Clemson, from the pic it looks like you put dykem on the camming surface not the bottom of the rail. I think this is what vlad is referring to. Cutting the root of the handle instead of the receiver camming surface. Not cutting the bolt to avoid notching the bottom. Of course I could be wrong.

-Don

 

Thanks, Don, for clarifying that! Vlad, I'm sorry that I missed what you were asking. You are absolutely correct. You do NOT want to cut the bridge or camming surface of the receiver. The confusion comes from the fact that the bottle of Dykem that I used is one of those self-contained items with an ink pad on the top. I just got sloppy with it when I marked the rail. some spilled over onto the side of the bridge in the cam area. I assure you that I did not cut any of that away! You are also right about modifying the bolt in that area. This photo shows the filing taking place on the bolt. The focus is somewhat fuzzy, so I did not originally include this one, but it shows that I am filing the front of the bolt handle down to the original bolt root contour. This photo shows the filing of the weld "lump" in progress. I continued filing until it was down to a totally flat contour, which was the original front of the bolt handle.

 

BoltHandleWelding004.jpg

 

Keep me straight, guys!

 

Clemson

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Could you walk through the steps that you took on that action to the point it is in the pic? Where do you plan to go after that? More polishing? Send away for hardening? or has that already been done. It all looks so nice! and clean!

 

LC: I will see if I can locate the previous posts on this rifle and pull them back onto this page for a bit.

 

Clemson

 

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Clemson,

 

Donmarkey is correct about what I was asking. Glad to hear you where not redefining the the cmming surfaces.

 

As an aside, are you in Clemson or di you go to Clemson or both? I lived in Cola. from 80 to 85 and have been in Charlotte ever since.

 

Vlad

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... are you in Clemson or di you go to Clemson or both? I lived in Cola. from 80 to 85 and have been in Charlotte ever since.

 

Vlad: I went to Clemson when dirt was young. I now live in Greenwood, about two hours from you. Any time you (or any of the rest of you out there) want to drive down here, send me a PM, and I will give you the shop tour and the proverbial cup of coffee. :P

 

Clemson

 

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