La Bounty action kit

[Someoldguy]

The Viper fixture allows you to adjust the action in multiple planes so that you can get exact concentricity To determine that concentricity, most use some sort of ground mandrel and bushings in the raceway. Manson makes a dedicated ground rod for this. Some use the Manson or PTG raceway boring jig for this as it has a precision ground dowel as part of the pilot and uses the same bushings. Since you need two bushings for an action and because there can be considerable variation between actions, you'll need a set of about 10 bushings to cover all the possibilities (I only have about 6 or 7 as I buy them as needed). Also, for some reason, Manson made a run of their rods that were ground centerless. Centerless grinding is great for super consistent diameters across the length of the grind, but like a barrel bore, the dowel will all end up a little banana shaped by virtue of the way a centerless grinder works. Make sure there is a cone at each end to ensure that it was ground between centers, or it'll be useless as a means of finding concentricity (I have a video of this somewhere if anyone wants to see. The centerless ground rods have up to 0.0030 runout.).

I see, so this is a lot like centering a barrel bore with a range rod and bushings.

Thanks. I think I follow the idea now.

 

[Cloudrepair]

I'm not sure I understand the question. Both front and back. How could you hold just the front (and why would you if you could)?

Maybe this will help
I'm setting this one up and I'm holding the front ring only to keep from flexing the action and skewing the results.

 

[GenePoole]

Maybe this will help
I'm setting this one up and I'm holding the front ring only to keep from flexing the action and skewing the results.

That does help.

Obviously, the set-screw spacing on my fixture would not allow that.

 

[Cloudrepair]

That does help.

Obviously, the set-screw spacing on my fixture would not allow that.

Originally I was just going to suggest adding another set screw between the front two on your fixture.

 

[tobnpr]

Far as the LaBounty collar...I use it.
Nothing special about it, it's a sacrificial collar. I use a Manson mandrel between centers with the collar, make a truing cut, then set up the steady. If all you want is to true the receiver face, a tight mandrel between centers is all you need. The collar allows you to get into the receiver to cut threads/lug abutments like the receiver fixture by holding it in a steady.