Welding Bolt Handle

K

kuch0778

Inactive
I have a Mauser M48 and am sporterizing it. I have a low scope safety, timney trigger, scope base and have reworked the stock. I now want to cut and weld the bolt handle. I have a lincoln mig welder among a shop full of other tools. I was wondering what i can use for the new handle, it shouldnt be too hard to get a knob, i guess i could get one from midway.

Can use a regular 1/2" bolt? does the type of steel matter?

What about temperature? Most people use a heat sink and heat sink paste, but im guessing you would still have to weld and let cool, then weld more?

Thanks for the help

Nate
 
have you considered heating/bending/reshaping the existing bolt rather than a new handle? in either case you will need heat sink paste. As to a mig welder, you're not dealing with a lot of metal, seems that acetelene would be better.
 
Hey Nate,
As a retired Master Gunsmith, I forged & welded hundreds of military bolts to sporter configuration to use a scope. The primary concern is the temper of the bolt body and your ability to maintain the hardness. I used Buehler bolt bending blocks for forging & a Williams bolt welding fixture to weld a new bolt handle to the bolt body. With both applications, an aluminum bolt block(outside) & aluminum inner bolt body rod are used to absorb the welding heat to minimize loss of temper. Depending on application, I used O/A for forging and O/A or MIG for weld-on handles. If you use MIG, you must use solid wire(ER70S-6) & C25(75%AR/25%CO2) shielding gas. Do not use flux-core because of the possibility for slag inclusions that will lead to porosity & a weak weld joint. I would strongly advise you to do some serious practicing on scrap metal of similar size parameters to get the "feel" of welding this kind of application. Also, a MIG with at least 140A would be needed. Hope this gives you some food-for-thought to ponder. I'm sure others will chime in with their thoughts. Good luck..... Denny
 
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i would like the bolt handle to look similar to this. Which is why i would rather weld instead of bend. I have a 135A lincoln MIG with gas and solid wire. I'm wondering why the weld has to penetrate through the whole handle, i didnt figure it would ever see that much force.

Do the types of metal need to match? chrome moly? i like the look of the threaded bolt knobs
http://www.midwayusa.com/viewProduct/?productNumber=180663

can i weld a grade 8 bolt as a handle??
 
kuch, while I will get flamed and almost everyone will disagree, I think you can do okay with less than perfect on a bolt handle. I'm not a precision welder, but I've arc welded a 21' disc harrow tounge together before so don't think I have no knowledge of the subject.

For this app, as with most apps, you need to weld like metals. The weld DOES NOT have to penetrate the entire handle as long as you relieve or "boat tail" (been a long time since I've touched a welder guys, can't think of the term) at least 1/8", and this would give you 1/4" weld penetration all the way around even with a cart welder. That would be plenty to hold everything together, assuming you did your homework accordingly. My .02, but not from a retired master gunsmith. FWIW, you shouldn't have much in the material so I would make 2 or 3 of them while I was working on the project. If you do snap one, which I don't think is too likely if you're a reasonably experienced welder, then you can swap it out.
 
I have done a bunch of bolt handles also, and I prefer to forge down the original, using bending blocks (Brownells). I am well aware that it doesn't happen when the welder knows what he is doing, but I have seen too many welded-on handles come off, something that doesn't happen with a forged handle. I consider the screwed on type an abomination. Yes, they work, but IMHO they look like hell.

P.S. FWIW, I used a piece of electrical ground rod as a heat sink and took it down to fit tightly inside the bolt. Ground rods are copper and I think make a better heat sink than aluminum. And keep the front end with the lugs cool with a damp rag.

Jim
 
FWIW, the references to holding the bolt's temper, above, in my experience have more to do with the cocking cam surface adjacent to the handle root, than the locking lugs.

If the cocking cam loses it's casehardening, it will gall with some use, making the rifle harder to cock/open - adding to the force needed to lift the handle.

Use good heat sinks, as above, and deeply chamfer all edges to be welded, so the weld penetrates as deeply as possible.

Bending a forged handle is strongest/best, but not for everyone, since some may prefer a different style knob, that's hard to make from the issue knob - say, one like a Rem 700 flat/checkered knob, or from some other admired rifle.

.
 
Kuch778, the problem with bending bolt handles, after they are bent they are too short, I started by cutting the handle off at an angle, rotating 180 degree and welding them back, not much bending, the biggest waste is Brownells bending blocks, to thick, too tight for the Mauser bolts and will not fit all Springfields, I will say the Brownell blocks are a good start, with an hour of work with a mill they become a very good bolt bending device

A better option is to bend the handle, cut the knob off and add another cut-off knob with part of it's handle, the extra extension will extend the length with less welding, at the bolt.

Two friends do a lot of work on Springfields, they come across drill rifles that are welded, sometimes the weld includes the bolt, there are times the only part of the bolt that is salvageable is the bolt handle, I get handles from them for free or close to nothing and use them for bolt handle extensions.

Something I am am trying now that eliminates welding is cut the ball off with a fly cutter to the same diameter as the bolt handle, then chuck a ball in a lathe and cut a hole through it that is .010 smaller in diameter than the outside diameter of the bolt handle, then I heat the knob (big time) and place on the handle, this method extends the length of the handle from 1/2 to 2/3 the diameter of he knob, if falling off is a concern, weld the ball to the handle through the hole in the bottom of the knob.

Heat sink, use heat sink paste and a bolt sleeve, mill/cut slots in the threads of the sleeve to aid in cleaning threads, I also use the headed plug.

Think about this, find a tub, fill with water, put your arm in the water with the bolt in your hand with the cocking cam sticking up, heat the bolt, when it gets to that magic color, pull it under, I did not say do it, I said think about it, or do nothing and worry about it.

F. Guffey
 
My local tig master got up to $65 to weld one on.He does beautiful work,but on a "tool" rifle,it was a bit much.

I figured this out,and it works for me.

There is a threaded heat sink that Brownells sells.Good idea.You want something to support the threads for the cocking piece.

Notice the bottom flat on the bolt handle root serves as a stop to clock the bolt when it is closed by stopping on the reciever rail.Thats important.

Right about where the edge of the rail is,where I want my bend,I hacksaw about 70 % through the bolt handle.Assume the rifle is horizontal.We are cutting down.The idea is the thin spot creates a hinge to heat for the bend.When the bend is made,very little filing will be needed on these surfaces

Now,use a small acetylene tip to heat the thin spot red and the handle will bend easily down.bend it so it is almost 90deg down,75 anyway,

The notch actually keeps the bolt handle from shortening in the bend,so you get a longer bolt handle than bending

This near vertical bend will seem too much,but later,after the weld,you heat the handle about 1/3 of the way to the knob and bend the lower part out.Study a nice bolt handle.

Anyway.Back to the cut,then the bend.Now,with no fixtures,you have an open "V"to weld up.We used the same flux core Lincoln you have.wels a little at a time,clean it up,if you see a flaw,grind it out.Dont put a lot of heat in.

build up enough to square it off.


The top contact wheel on a small 1 by 42 belt sander grinds a nice radius in the handle where it clears the scope.A 1/12 or 2 in flap wheel in a 1/4 in die grinder is good,too.


Think about working the knob a bit before hand.Its a little easier.You can reduce the ball dia by hand if you are careful.Maybe 5/8 is good.So,start by filing 4 flats to make a square,a bit over 5/8.Even,uniform flats.Then,file the corners off to make an octagon.Now,file these corners off.Now,as you blend and shape it,you can make it a bit pear shaped instead of sperical.do not remove material from the length,but from the upper part of the ball.The handle will appear a bit longer..Go slow,look and think before you file.

Good luck
 
I've never seen a rebent handle that looked worth a flip and I've seen a few. They're too short also.
 
Keep in mind that in addition to the bolt handle being brazed on that the locking lug section of the bolt is also brazed on.
 
Hi, Savage99,

The discussion is on a M48 Yugo Mauser; I guarantee that neither the bolt handle nor the locking lug area is brazed on.

Jim
 
I am not a gun smith at all. But i am a Welder and A Certified Welding Inspector with the American Welding Society. Your best bet would be to find some one who has the ability to ("Heliarc" , "TIG" ) Gas Tungsten Arc Weld. The strength will come from the type of preparation, filler metal used, base metal, amount of heat input, and last and most important, rate of cooling. I am not sure where you are located , but most machine shops would have the ability to do this. Or if you know any Pipe welders...(they are normally the best Tig welders) JB
 
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