Gunsmithing threading barrel help

[KYS]

I am about to start threading my own barrels with the help of a friend and his full scale machine shop. He has access to many different machines BUT my dilemma is this... what equipment do I need to allow myself to thread my barrels WITHOUT taking the barrel off the action? Im looking to see if there are any special jigs or fixtures I might need for the mill or cnc. George at GAP had mentioned something about being able to thread barrels with the receivers still attached to them with no problem....

My first project is my M40A3 build. Its the real deal, straight from a military armorer in Quantico. I need to thread the barrel and install my YHM Phantom QD mount. I really dont want to have to remove the barrel from the action and risk messing up their paint job. Yes I could do it again, but it wouldnt be how they did it.

Any and all help is appreciated!

 

[6.81star]

Re: threading barrel help

I'd cut them in a 4 jaw and on a manual lathe if your friend owns a machine shop and can machine he'll be able to show you how. You 'll need a spider plate at the rear of the spindle or some sort of bushings to center it up in the tube to keep it from flopping around.

 

[Revenge Seeker]

Re: threading barrel help

Good luck getting it indicated. possible, but not easy.

 

[KYS]

Re: threading barrel help

Thanks 6.81star - Ill tell him that. He is well versed in the firearms community, I cant say anymore due to confidentiality standards but he has not started threading barrels on bolt guns with actions attached. I guess I could buy the action wrench and take the barrel off if I have to....


Anymore helpful hints out there? I really dont want to mess this barrel up!

 

[cpermd]

Re: threading barrel help

Unscrew it.

CP

 

[Victor N TN]

Re: threading barrel help

I've done it on an old South Bend 10" tool room lathe a bunch of times. Like stated above, a well made "spider" 4 jaw adjustable for the back of the headstock is key to keeping it from flopping around.

 

[Hateca]

Re: threading barrel help

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kyshooter338</div><div class="ubbcode-body">Thanks 6.81star - Ill tell him that. He is well versed in the firearms community, I cant say anymore due to confidentiality standards but he has not started threading barrels on bolt guns with actions attached. I guess I could buy the action wrench and take the barrel off if I have to....


Anymore helpful hints out there? I really dont want to mess this barrel up!

</div></div>

Even taking the barrel off is not going to help you indicate the barrel the ideal way. The only reason you should need to remove the barrel is if the head stock is too long for your barrel. If it is there are other set-ups and jigs you can use to get around this as well and still be able to indicate the end you want to work on.

If the barrel is long enough even with the action attached you can still indicated the barrel through the head stock. You will need a spider on the outboard of the spindle bore, a four or six jaw chuck, an indicator rod, and two dial indictors to indicate the bore to run true on only the end you are working on before you start cutting threads.

Do not think dialing in both ends to read zero, or indicating off the outside of the barrel diameter is good enough to cut threads, it’s not. Doing it this way you haven’t dialed out the bore run-out.

 

[300sniper]

Re: threading barrel help

i can "through the headstock" thread the muzzle on a barreled action that is at least 19" from the recoil lug. if the machine shop has a lathe with a spindle short enough to fit your barrel from the recoil lug to the muzzle, you should be good to go, with a spider chuck on the back, of course.

 

[KYS]

Re: threading barrel help

thanks a bunch guys! your input was all put down into some notes and we are going to try on a scrap barrel first.