Barrel threading

[DHuffman]

So this morning with Wyatt helping we chambered the barrel.

First I trued the shoulder of the JB'd nut to the barrel threads. Then I started facing my tenon threads to length from the shoulder to the breech to get my .010" boltface to breech clearance.

Then reamed the chamber.






I lost count of how many plunges to get to depth.

[DHuffman]

Didn't take a lot of pics from then on so I'll cut to the chase LOL

Shots 1 & 2, random ammo loaded for other gun. 150 yards 15+ wind from 10-11 o'clock




Shots 3, 4 & 5




Shots 6, 7 & 8

[DHuffman]

Old 4-16 vortex with a heavy reticle.

[autoxforfun]

Dave, I gave threading away from the headstock a shot today.  I ran the chuck in reverse and turned my tool upside down.  Worked like a charm.....



I have a question regarding the single point tool that you were using.  I use inserts and when I turned the holder upside down, the insert worked great but I lost all of the clearance on the left side so getting close to a shoulder was not possible.  Here are the tools that I used.  I am looking for a different tool holder....but thought I would see what you use.

[DHuffman]

Dave, I gave threading away from the headstock a shot today.  I ran the chuck in reverse and turned my tool upside down.  Worked like a charm.....



I have a question regarding the single point tool that you were using.  I use inserts and when I turned the holder upside down, the insert worked great but I lost all of the clearance on the left side so getting close to a shoulder was not possible.  Here are the tools that I used.  I am looking for a different tool holder....but thought I would see what you use.

We have a specific holder for the inserts that puts it to the left when it gets inverted.

It takes an IR insert as well but that gets you back closer to the chuck also.

I wouldn't be scared to make a smaller relief and start right next to a shoulder.

I won't be back north until Tuesday but I can get a pic then if you need it.

[WHuff]

Dave, I gave threading away from the headstock a shot today.  I ran the chuck in reverse and turned my tool upside down.  Worked like a charm.....



I have a question regarding the single point tool that you were using.  I use inserts and when I turned the holder upside down, the insert worked great but I lost all of the clearance on the left side so getting close to a shoulder was not possible.  Here are the tools that I used.  I am looking for a different tool holder....but thought I would see what you use.

I am Dave's son Wyatt, the tool holder you will want will be the exact same that you have but just order a "left hand" or "off hand" version of it.

You will also need to order the same inserts but instead of them being 16 "ER" AG60 inserts for example, they will be "IR" instead of "ER" so they adapt to your left hand holder. That should fix your clearance problem.

[autoxforfun]

Thanks Wyatt.  That was exactly was I was looking at ordering.  I was also looking at using an internal threading bar and using it on the back side.  Doesn't have the visibility and rigidity of the other options. 

[WHuff]

No problem Bob!

We recently picked up a couple internal offhand threading bars as well, but I will be using those to do blind hole threading away from the headstock with this same method to get truer and better internal threads and also not have to stock big diameter taps.

[DHuffman]

JB'd the nut on the Shilen Select Match barrel this morning. It's a 28" full bull small shank in 6.5x47 Lapuas with an 8 twist. I've been waffling around for a week on whether to permanently shoulder this barrel or leave it nut adjustable.

Is a very good barrel and I suppose there's a risk by setting it back +/-.030" it may not shoot as well but I'm trying to gain skills on the machine and I'm over nut barrels after getting this equipment and doing the other barrel in this thread.

So the course is set and there's no turning back.




All indicated in the machine to half a half a thou

[gman47564]

Dave is the nut a good solid connection with the jb weld.. I've always thought that would be a good way to turn a savage into a switch barrel platform.. I think we even discussed it in a older thread at one time..

[autoxforfun]

I am with you Dave.  I am moving away from barrel nuts as I need to replace barrels and going 100% shouldered.  I do have a couple prefits that I will still use and just keep the nut for them.  

The only concern I have in setting the barrel back is that you are running the reamer into some pretty nasty material.  I worry about damaging the reamer.

[DHuffman]

I am with you Dave.  I am moving away from barrel nuts as I need to replace barrels and going 100% shouldered.  I do have a couple prefits that I will still use and just keep the nut for them. 

The only concern I have in setting the barrel back is that you are running the reamer into some pretty nasty material.  I worry about damaging the reamer.

No doubt about it.... If it were a large shank I'd cut it off like the other.

[autoxforfun]

Something that I changed on my lathe was to adapt the cooling pump to supply cutting oil thru the muzzle and provide a constant oil flow to the reamer.  It has really improved the cooling of the reamer and the amount of cutting before needing to pull the reamer back out....mainly to clean the reamer.





I don't use a 3-jaw chuck for my barrels but this was any easy way to generate some photos.

[DHuffman]

Something that I changed on my lathe was to adapt the cooling pump to supply cutting oil thru the muzzle and provide a constant oil flow to the reamer.  It has really improved the cooling of the reamer and the amount of cutting before needing to pull the reamer back out....mainly to clean the reamer.





I don't use a 3-jaw chuck for my barrels but this was any easy way to generate some photos.

Very nice Bob I've been thinking about something similar.

I did some work on the 47L barrel this afternoon/evening.
Got the nut trued, the tenon set and went ahead and set back the chamber. Grabbed the carriage wheel instead of the cross slide and shaved off more than I intended on the nut 😵�💫 so my setback ended up being over .300" after I corrected that.

One thing I found interesting was the go gauge had .150" protrusion set up as a nut prefit from Criterion. After setting my tenon and giving the bolt head / breech .009" clearance I ended up with .125" protrusion on the same go gauge for the bolt to close on it.
I know it's all web at that part of the case but that's still a lot more support for it regardless.

Chamber reamed well and the reamer appeared no worse for well when done.

[autoxforfun]

Dave, I had the same realization when I started shoulder chambering for the Savage action versus using the barrel nut.  Seems like the prefit barrels allows for a LOT of bolt to breech clearance.  When I set this to be in the 0.008"-0.010" range, I end up with around a 0.126" go gauge protrusion.  I guess for the prefits, it makes it quicker for the production run to not get too close and make sure they have enough margin so that every barrel will fit with the correct headspace.