How to hold a TC Contender barrel for threading.

[Ksracer]

How would you guys hold this Octagon barrel to thread the muzzle? It's about 8" long overall and has a 1.2" radius at breech.

I turned the job down because I don't have time for odd stuff at the moment, but my thoughts were a Viper type set screw fixture with a 2.5" bore (mine is only 1.9"). Or use a 4 jaw with the large part hanging behind the jaws and use shims to true it up.

Just curious how others might do it.

 

[paperpuncher]

Put it between centers and drive it with a dog

 

[Ksracer]

Put it between centers and drive it with a dog

Good idea, but it also needs to be cut back and re-crowned.

 

[Dusty Stevens]

Id use the viper fixture. Plenty of meat to bore

 

[boltfluter]

I would make an Octagon shaped(internally) 2 piece split bushing out of aluminum and be off to the races. Round on the od of course. Make 2 if you want to use the Viper type of setup. Or, do it between centers with an aluminium cap on your live center so no need to re-crown. Many ways to do this job. Good luck!
Paul

 

[xr650rRider]

Here is a link to a method that Mike Belm uses. Yes, it gets poo-pooed for being messy, etc, etc. But they've never tried a contender or encore barrel. It takes at least 2-1/2" bore to accommodate the lug and get it on center. Short barrel like you have a big bore viper type jig might work. Might have to make bushings out of epoxy. I can do around 22" and the lug out back of PM-1340GT spindle but any shorter, have to do like Mike Belm.

Mike Belm method for Encore threading

Most would send to Chad Dixon for 5 axis thread milling in CNC.

LongRiflesInc

https://www.facebook.com/video.php?v=256956826280400

 

[Tucker65]

I did one of these not too long ago but it wasn't an octogon barrel. I made an adjustable cat head that rides in bearings and attached it to my steady rest. Dialed the breech end in the 4 jaw then indicated the muzzle bore by adjusting the set screws in the cat head. I got the idea from a picture I saw that someone else made.

 

[LVLAaron]

I did one of these not too long ago but it wasn't an octogon barrel. I made an adjustable cat head that rides in bearings and attached it to my steady rest. Dialed the breech end in the 4 jaw then indicated the muzzle bore by adjusting the set screws in the cat head. I got the idea from a picture I saw that someone else made.

That's really cool! I've seen a lot of setups in my search for knowledge... that is the only one I've seen set up like that. I like it!

 

[Ksracer]

I did one of these not too long ago but it wasn't an octogon barrel. I made an adjustable cat head that rides in bearings and attached it to my steady rest. Dialed the breech end in the 4 jaw then indicated the muzzle bore by adjusting the set screws in the cat head. I got the idea from a picture I saw that someone else made.

That's pretty cool.

I've got an old live center that I removed the point on and replaced it with a small set screw type "spider" that rotated. I used to use it to hold the front of a bolt to true the lugs. Then I would put a sacrificial puck around the bolt body, true the od and run it in a steady to work on the bolt face.

And now that you mention it, I might have an old cats head in the back of the drawer that's short enough to get this barrel in. Then just throw the whole thing in the 4jaw. I don't mind spendy a few minutes swapping chucks, I just didn't want to start making odd ball fixtures for it.

 

[Ksracer]

Screw it. It's for a friend and he didnt want the trouble of shipping it. I got it within .0005 over 2.5" without much hassle. I gently cut a center in the end and used the tailstock to make sure it didn't move.

Big ugly chuck + strategically placed shims =
Sketchy ass shit FTW

 

[Dusty Stevens]

You did a fine job

 

[Ksracer]

You did a fine job

ThankYou

 

[boltfluter]

I did one of these not too long ago but it wasn't an octogon barrel. I made an adjustable cat head that rides in bearings and attached it to my steady rest. Dialed the breech end in the 4 jaw then indicated the muzzle bore by adjusting the set screws in the cat head. I got the idea from a picture I saw that someone else made.

Very ingenious, I like it. Sometimes you have to think way outside the box!
Paul

 

[GNERGY]

I can do Contender barrels and longer ones where I don't have to remove action with this ball bearing steady rest I made.
Tarey
Will have to find the pics of the contender barrel dialed up and threaded.

 

[tobnpr]

Good idea, but it also needs to be cut back and re-crowned.

Here's what I do...
After setting up on the dead center/dog; turn a short bushing with an internal taper to match the barrel an inch back from the end, behind where you'll be cutting the tenon.
Can also use a straight bushing, release agent on the barrel and epoxy inside the bushing so it forms a perfect fit to the muzzle end.

Then wrap a single layer of thin paper around the barrel where the bushing will go and slide the bushing over the paper and tap tightly into place. The paper helps keep the barrel from spinning in the bushing.
Muzzle end in a live center in the TS, make a truing cut on the bushing- this makes the bushing concentric to the bore. Set the bushing in the steady, couple of indicators on it to confirm it doesn't move, back the TS out of the way, and start cutting. Light cuts are mandatory- you don't want the bushing to spin on the barrel.

 

[LVLAaron]

For that little stub of a barrel I think I would have just shimmed it and stuck it in one of these two jigs.

 

[xr650rRider]

For that little stub of a barrel I think I would have just shimmed it and stuck it in one of these two jigs.

Those are at least 2.5" bore? What you going to do with the lug on chamber end of barrel?

 

[urbanrifleman]

I can do Contender barrels and longer ones where I don't have to remove action with this ball bearing steady rest I made.
Tarey
Will have to find the pics of the contender barrel dialed up and threaded.

I would gladly pay for a bearing steady if someone would make me one.

 

[Ksracer]

For that little stub of a barrel I think I would have just shimmed it and stuck it in one of these two jigs.



View attachment 1391550View attachment 1391551

That was my thought when I took the job on, but I didn't realize that little block on the breech wouldn't fit inside my "Viper" jig, and mine doesn't have enough meat to bore it out. I thought might be able to use and old cats head, but it turned out to be too long and had the same issue as my Viper.

This is probably a 1 time deal and the 4 jaw was just the quickest way.

 

[LVLAaron]

I would gladly pay for a bearing steady if someone would make me one.

It's a spider and a bearing. You can make one!