Cut first barrel threads

[FuzzNut]

I used a HSS threading tool and cut threads on a junk .224 barrel from PSA (don’t wanna get into it). I’ve never cut threads and have muzzle devices that I don’t want to tear up.

What is best to cut a “good enough” crown with. ? I used like a 30 degree countersink but that’s a junk barrel so doesn’t matter.

Do you guys thread indicated off bore with a steady rest ? Or on centers ? Or don’t worry about it and just thread it close to chuck ???

I have a WAY out ruger factory barrel, 110 thousands off center, that tore up my 30 cal cab before .. warranty no longer covered bc company out of business, don’t wanna do that again. I ought to align those threads myself but the barrel is 16in and I “technically” can’t cut off and shorten it.

I should of never shot through a $1000 chunk of metal with that barrel.. hindsight 20/20.. back then when I first got can I was just excited and wanted to try it on everything

Thought of cutting threads off and retreading with a small bushing that is threaded 1/2x28. … or just don’t worry about it.


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[FuzzNut]

Also- that 5.56 ranch rifle is one of my most accurate factory rifles. Even though the barrel is either drilled so far off center or was threaded so badly it still shoots great.


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[epanzella]

I don't know if it'll help you any but being as I don't have bore rods and bushings I start a rifle build by turning the blank on a center and a 4 jaw to make the bore concentric with the exterior of the barrel. I prevent bending the barrel in the 4 jaw by using a narrow bushing on the chamber end and protect the muzzle with a brass piece that is .001" over land diameter and center drilled.

 

[Flyinfool]

If you really do need to shorten and rethread your 16 inch barrel there is a proper LEGAL way to lengthen the barrel to return it to legal length. You have to permenantly attach something (like a muzzle break?) to the end of the barrel. I do not remember the specifics but "permanent" involves both pinning and welding.

 

[pdentrem]

Maybe a wild idea.
Make a smaller threaded section by turning down the original threads and make a threaded bushing to build it back up to the muzzle brake threads. Turn between center to make everything concentric with the bore. Use a low temp silver solder to hold the bushing solid to the barrel or Green Locktite.
Pierre

 

[Nogoingback]

If you really do need to shorten and rethread your 16 inch barrel there is a proper LEGAL way to lengthen the barrel to return it to legal length. You have to permenantly attach something (like a muzzle break?) to the end of the barrel. I do not remember the specifics but "permanent" involves both pinning and welding.

That is correct. With the muzzle device screwed on, if the length is greater than 16" It's GTG. Pinning and welding makes it legal.
If I remember correctly, the measurement is from the bolt face to the end of the barrel.

 

[Flyinfool]

I thought the barrel length was from the tip of the firing pin to the end of the barrel? Not much of a difference but if you are cutting it that close.....
I know that is how it was measured for handgun deer hunting in WI. All wardens carried a 5 inch dowel with them to drop down the barrel of an unloaded handgun to check for the required 5 inch barrel length. This way thy do not have to mess with retracting the firing pin and having to know the working of every gun out there. the state has since removed the 5" rule for deer hunting handguns.
I always stat with my barrels at least 1/2 to 3/4 inch longer than the legal minimum to leave room for a couple of crowning's should they ever be necessary.

 

[Nogoingback]

My son just went through that with an AR build, and that's what he told me. Of course, a revolver doesn't have a bolt face,
and Wardens probably only wanted to carry one dowel with them. His first flash hider measured a bit under 16", so he
bought another: measured 16 1/4" so we had some margin there.

 

[Scott-ak]

You MUST align the bore to the machine. I prefer range rod, grizzly rod or long reach indicator over working between centers. I have done it tween centers and made cone bushings with a tightly fitted pin on the side that goes in the muzzle and no pin on the breach end. It's simply too much extra work to make the bushings and it's really only good for one time use. If the barrel won't go thru the headstock and reach a spider on the end then tween centers is your best option. You can work off a steady, but again it's more work. There is a ton of educational videos out there. Watch some and then practice threading, ALOT

 

[redgrouse]

One thing I don’t understand is the 16” barrel length? Guess it’s something in your legislation ? However as far as screw cutting a barrel the best way is between centres using spuds at either end for the centre’s. I have done many hundreds over the last 45 years and this method guarantees truth.
Pierre’s method of a “repair “ to maintain the length will work well or you could use a screwed item with the finest thread you can and use an adhesive. If you are to use this ensure the OD of the thread is less than the root of the final thread (1/2” UNF ? ) and of course it’s root dia is considerably larger than the bore dia. Personally I would go for the soldered sleeve because this minimises metal removal from the barrel.

If you are to use solder I would consider Tin and yes it is strong enough. If you want to use an easy silver solder I would recommend you place a loose fitting rod inside the barrel “lubricated” with Black Lead — the stuff grandma used to shine up the fire grate with. This will prevent any oxidation of the barrel interior and leaves only a carbon deposit, easy to clean out. Usual caveats apply ! There are of course other materials you can use to prevent oxidation but I know this works, passed to me by an old Chap in Birmingham many years ago.