Spindle size and muzzle threading

[jareese]

Edit: Good info you guys, but most of you are missing the point of the question. I'm not asking HOW to do it. I'm asking what spindle bore size you have and if you're able to fit a barreled action into it if need be.


I spoke with another gunsmith the other day and he said he has a 2" spindle bore and does not need to remove barrels from receivers. In doing some testing on paper, I drew out a 2, 2.5, 2.55, 3, and 3.125" circles. I then screwed a stub onto a Rem 700 short action with an aftermarket PTG .250 recoil lug, centered it up to the witness mark in the center of the circles.
No way it would fit into a 2" bore without the lug hitting. 2.55 was very tight - I think there would be issues while dialing it in and stress would be put on the barrel. Am I wrong?

What spindle size is your lathe? Do you need to remove barrels from receivers in order to thread muzzles? What are you finding?

 

[GT Accuracy]

I spoke with another gunsmith the other day and he said he has a 2" spindle bore and does not need to remove barrels from receivers. In doing some testing on paper, I drew out a 2, 2.5, 2.55, 3, and 3.125" circles. I then screwed a stub onto a Rem 700 short action with an aftermarket PTG .250 recoil lug, centered it up to the witness mark in the center of the circles.
No way it would fit into a 2" bore without the lug hitting. 2.55 was very tight - I think there would be issues while dialing it in and stress would be put on the barrel. Am I wrong?

What spindle size is your lathe? Do you need to remove barrels from receivers in order to thread muzzles? What are you finding?

I think a lot of us have threaded a muzzle with the receiver on when it's a must do. I, and I only speak for myself, don't like to do it unless absolutely necessary. I made exensions for 16, 18, and 20 tpi barrel shanks to extend the workable length for my machines.

The problem with threading the barrel with it still on the action is that, if you coaxially indicate, you will have a mass that is large enough it will shake smaller lathes. Not to the point it's damaging but smaller machines, like the sharp 1340 and the Acra 1340 VS, can get a good shimmy going. On machines in teh 2,400 lb + range it's not nearly an issue. Turning your RPM down to 600 or less, even on the light machines, makes things much calmer.

 

[SKWERLZ]

I only have 1.24” spindle bore (restriction at collet shank area) so definitely action off for me.

 

[tobnpr]

I have a short spindle Sheldon so most barrels work just fine with the receiver outboard the spindle.

If it's too short a barrel for that to work, I'll stick a mandrel in the bolt raceway and do it between centers. If the crown doesn't need to be done, I use a crown saver or brass/delrin pin in the bore with the live center. If it needs crowning as well I set up in the steady with a sacrificial collar.

I've never pulled a barrel to do muzzle work.

 

[Jonnyofalltrades]

I have a short spindle Sheldon so most barrels work just fine with the receiver outboard the spindle.

If it's too short a barrel for that to work, I'll stick a mandrel in the bolt raceway and do it between centers. If the crown doesn't need to be done, I use a crown saver or brass/delrin pin in the bore with the live center. If it needs crowning as well I set up in the steady with a sacrificial collar.

I've never pulled a barrel to do muzzle work.

This is almost exactly my process for muzzle threading when I start with a fully assembled rifle.
It works really well, and is as quick of a setup as you can get.
With a new barrel, it is nice to do the muzzle threading with just the barrel.

To the OP's question, it's pretty easy toq flex a sporter weight barrel 3/8"-1/2" with a lathe chuck. Wouldn't surprise me if that has happened here.

 

[ELR LVR]

I spoke with another gunsmith the other day and he said he has a 2" spindle bore and does not need to remove barrels from receivers. In doing some testing on paper, I drew out a 2, 2.5, 2.55, 3, and 3.125" circles. I then screwed a stub onto a Rem 700 short action with an aftermarket PTG .250 recoil lug, centered it up to the witness mark in the center of the circles.
No way it would fit into a 2" bore without the lug hitting. 2.55 was very tight - I think there would be issues while dialing it in and stress would be put on the barrel. Am I wrong?

What spindle size is your lathe? Do you need to remove barrels from receivers in order to thread muzzles? What are you finding?

If you dont want to remove barrel from action
--- Turn between centers to thread the muzzle
Easy and accurate
---
Ensure your tailstock height is close enough
I don't worry about .002" or .003" height differential at more than
30 inches distance between centers and only threading .700" of length
I WOULD worry about .020" or .030" height difference

 

[Jonnyofalltrades]

If you dont want to remove barrel from action
--- Turn between centers to thread the muzzle
Easy and accurate
---
Ensure your tailstock height is close enough
I don't worry about .002" or .003" height differential at more than
30 inches distance between centers and only threading .700" of length
I WOULD worry about .020" or .030" height difference

Tailstock height is quite a ways down the list of things you need to worry about in lathe setup. It won't affect concentricity or angularity.
Between centers is a great way to reduce angular misalignment.
The only big variable left is whether the original crown is concentric with the bore. Fortunately, there are ways to get that really close, without killing half a day.

 

[jareese]

Good info you guys, but most of you are missing the point of the question. I'm not asking HOW to do it. I'm asking what spindle bore size you have and if you're able to fit a barreled action into it if need be.

 

[Jonnyofalltrades]

Sorry.
Mine is 1.9".
Most rimfires will fit, nothing else.

 

[jareese]

Sorry.
Mine is 1.9".
Most rimfires will fit, nothing else.

No worries man, appreciate the info