Bolt fixture

O

oldpup223

Guest
Does anyone have a picture of a fixture used to open up a bolt face.
I would like to make one and just need a good look or maybe some ideas.
Thanks
 
Works for me.

I've seen photos of a fixture that had a round section then the rest of it had a v-groove in it. I just couldn't see it being any good as there wasn't any way to run a dial indicator on the bolt body to make sure it was running true. Below is a photo of how I set up my bolts to true the bolt lugs. 2nd photo is setting the steady rest points. 3rd photo is to face off the bolt face or to open the bolt face, fill the old extractor groove and get it ready to mill for a sako style extractor. The photos are old and were done several years ago when I had a Jet lathe. I still do it the same way except now my steady rest has roller bearings with a different lathe.

boltsetup2.jpg


steadyrestsetup.jpg


boltfacetrue.jpg
 
thank you for the confirmation. I had thought that there was no reason not to do it in a four jaw.
Thanks
 
Justin,
Those are four screws to dial in the end of the bolt nose. They also hold it captive, but not by much.

Mike
 
Mike Bryant said:
Justin,
Those are four screws to dial in the end of the bolt nose. They also hold it captive, but not by much.

Mike
Click to expand...

Mike,

Never seen that before...that's freakin' genius! A far better way of doing it than the way I USED to. Thanks for posting that.

Does your fixture hold the bolt captive enough that you can clean up the back of the bolt lugs, or turn down sections of the bolt for sleeving?

And I take it by the lack of sacrificial sleeve on the bolt body, that the bolts are sufficiently round enough to spin the indicated bolt true?

Thanks,
Justin
 
Zebra13 said:
Mike,

Never seen that before...that's freakin' genius! A far better way of doing it than the way I USED to. Thanks for posting that.

Does your fixture hold the bolt captive enough that you can clean up the back of the bolt lugs, or turn down sections of the bolt for sleeving?

And I take it by the lack of sacrificial sleeve on the bolt body, that the bolts are sufficiently round enough to spin the indicated bolt true?

Thanks,
Justin
Click to expand...

I'll center on the firing pin and check for runout on the bolt body before I go to the 4 screw jig. If the bolt runout is around a thousandth to two, I won't use the jig. If it's over that, then out comes the jig and the bolt body is dialed in to run true. I'll face the lugs off of that and the jig holds the bolt nose plenty well to face the lugs, but if the customer wants the bolt body bushed front and rear, then I center off the firing pin hole. That way everything lines up with the firing pin hole when bushings are cut down. When you start pushing the front of the bolt nose back and forth to indicate the bolt body in, then you know that the firing pin hole isn't in the center of the bolt body. Personally, I don't like bushings added to the bolt body. If I go to that trouble, then I'd rather ream the raceway to .705 and get a bolt to fit from Pacific. I had been getting bolts that were .704" if the raceway was reamed. If you have the receiver and bolt coated, then it's better to have a .703" bolt. I've had two bolts come back from coating that wouldn't fit in the .705" raceway because of build up of the coating.
 
Mike:

I had my doubts about alignment with the LaBounty fixture. I did mine your way. !. Last year while at TSJC teaching a class I had the opertunity to see and use a Labounty jig. I was amazed at how well it worked. 2. I made a jig that incorporates two catheads for truing bolts and it also works well. 3. One can take a Gretan Action truing jig and cut a slot for the bolt handle to protrude. and use it to dial in bolts also.
Nat Lambeth
 
Rustystud said:
Mike:

I had my doubts about alignment with the LaBounty fixture. I did mine your way. !. Last year while at TSJC teaching a class I had the opertunity to see and use a Labounty jig. I was amazed at how well it worked. 2. I made a jig that incorporates two catheads for truing bolts and it also works well. 3. One can take a Gretan Action truing jig and cut a slot for the bolt handle to protrude. and use it to dial in bolts also.
Nat Lambeth
Click to expand...
I tried the above setup in various ways and found the simplest was a mandrel with a taper or ball end screwed into the back of the bolt. This allowed the rear of the bolt to tip and conform to the steady rest. I found between the nose, firing pin hole and the bolt rear there was too much variation.
I can see if you just want to dial in the nose where the LaBounty in a four jaw or the action spider with a bolt handle milled cutout will work, but it still only aligns the nose as there's no way to get the rear indicated in with those fixtures.

Mike Bryant said:
I still do it the same way except now my steady rest has roller bearings with a different lathe.
Click to expand...
Hi Mike,
How did you convert the fingers to roller bearings?
I thought about this myself. Does it work better for bolts, mar the finish less than brass tips?
 
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Jonathan, they are 10-32's with brass inserts set into the set screws. The steady rest that came with my Kent lathe had roller bearings on the steady rest instead of brass tips. The steady rest that is in the photos was on a Jet lathe that I no longer have.
 
I do them as Mike does. To be honest I was a little surprised when adjusting the fingers and watching the test indicators, it works. You almost have to screw it up on purpose and again I was surprised when retracting the tailstock, the needles just don't move.
Last month I ran into a 700 head that was oval. After the factory soldered the head onto the bolt body, someone buffed it too much and you could easily see it was no longer round. I did not have fun dialing that one in.
 
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