Headspacing recommendations

L

Lucky Shooter A

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I need to slightly increase the headspace on a 6BR chamber----shining up the case heads-----for a barrel that is a good shooter.

My practice----right or wrong----has been to assure at least a slight crush fit for new cases and to use the GO gauge to establish a reference to repeat the chamber dimensions on other barrels. I left this one a little too short.

The barrel came out of the lathe with the set-up still good and should go back in OK. I work through the headstock and use a homemade Mike Bryant pusher.

Would appreciate any recommendations on a good way to do this-----with or without lube, etc.

Thanks.

A. Weldy
 
Lucky Shooter A said:
I need to slightly increase the headspace on a 6BR chamber----shining up the case heads-----for a barrel that is a good shooter.

My practice----right or wrong----has been to assure at least a slight crush fit for new cases and to use the GO gauge to establish a reference to repeat the chamber dimensions on other barrels. I left this one a little too short.

The barrel came out of the lathe with the set-up still good and should go back in OK. I work through the headstock and use a homemade Mike Bryant pusher.

Would appreciate any recommendations on a good way to do this-----with or without lube, etc.

Thanks.

A. Weldy
Click to expand...

If you are wanting to only take a couple of thousands off, remove the barrel and turn the reamer by hand. Put the reamer in a T-handle and put a light push against the handle as you turn it. Think about what you are doing and it should come out fine. Unless you really lean on the T-handle and turn it 5-6 turns you will not take out but about 0.001" per turn,

Or, turn the f/l sizer down a thousand or so.
 
Thanks for replies

Jerry, I have a couple of questions.

Should I use the same pilot bushing as before and should I use cutting oil ?

I've started using someone's rule-of-thumb estimate for tightening the barrel------about .002" reduction in headspace when tightening. Does this sound reasonable ?

I appreciate the help.

A. Weldy
 
Lucky Shooter A said:
Jerry, I have a couple of questions.

Should I use the same pilot bushing as before and should I use cutting oil ?

I've started using someone's rule-of-thumb estimate for tightening the barrel------about .002" reduction in headspace when tightening. Does this sound reasonable ?

I appreciate the help.

A. Weldy
Click to expand...
I don't know what fit pilot you used but use the tightest one you can reasonably insert and use a good grade of cutting oil. Make sure the bore is very clean before inserting the reamer each time.

If your thread profile is accurate in the action and in your barrel, there should be very little reduction in headspace after you have burnished the joint in place. By burnishing I mean, with the threads and tenon shoulder greased with a good extreme pressure grease or an anti-seize like Felpro, I snug the joint, about 10 15 fp, 20times or so, then I torque the joint to at least 100 foot pounds. I've never really tried to measure the linear reduction but I go by the final fit with a GO and NOGO gage and most of them have about 0.004" difference.
 
What I would do as well is set yourself up with a way to measure the headspace with a collar that fits over the tenon, depth micrometer and go gauge. That way you can measure -- cut -- measure -- cut -- measure...

I can snap a pic if you aren't sure what I am referring to.
 
Thanks Jerry, DSM

DSM, I have such a collar------copied it from a post here. Wouldn't leave home without it.

A. Weldy
 
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