Tuning the Pietta 1851,

[Pulp]

In a different thread I posted about an article in the Cowboy Chronicle about tuning a Pietta '51.

Here's a link to the article, as posted on TheOpenRange website.

http://www.theopenrange.net/forum/index.php?topic=5659

Some pretty good information in these two articles.

 

[Tom Krein]

Great info! THANKS for the links!

Tom

 

[Tommygunn]

Dang! for some reason my PDF program is having problems with this!

 

[SWC Bonfire]

I did not have to register to see the link.

Pretty good info. I wonder how much these guns would cost if they just did all that from the factory in the first place.

 

[JACK STEELE]

To Pulp

thank you for the great tips!

 

[jhon]

I've thought about the hand spring mod. If mine breaks again I'm doing it. I'm on my third one.

 

[Omnivore]

That is pretty good, apart from the frequent typos.

It also is at odds with several of the claims here, that wedge insertion is how you adjust for cylinder gap. According to this article, and it makes more sense to me, it is the arbor length that determines proper fit. If you can push the wedge in far enough to bind the cylinder against the barrel, your arbor is too short, and/or the barrel/frame dimensions are off. The comments on here had me confused until now-- I could mash my wedge in as hard as I dare and cylinder gap is not affected because the barrel is bottoming out against the front of the arbor.

I'd never seen a Ruger style hand spring and plunger, but that looks like a good and reliable system. Fortunately I've not had any trouble with my Pietta hand spring, but just in principle that plunger system is a better idea.

I'll have to try some of those Treso nipples and Rem 10s too.

 

[scrat]

Wow pulp good stuff thanks.

 

[SWC Bonfire]

Bump for this thread... did they ever follow up with a "tuning the Uberti revolver" installation? Because they mentioned that they would show how to fix an improperly fitted arbor on a uberti.

 

[madcratebuilder]

Bump for this thread... did they ever follow up with a "tuning the Uberti revolver" installation? Because they mentioned that they would show how to fix an improperly fitted arbor on a uberti.

Not that I'm aware of.

Fitting the arbor on a open top is not to big of job. Strip your gun down to bare parts. Insert the arbor/frame in to the barrel shroud hole with the barrel shroud at a angle so it's at the side of the frame instead of hitting the frame. You well see if the arbor is to long, (easy fix) or to short. (more work)
Best way to lengthen the arbor is to TIG weld it, build up the end and machine it back to the needed length. Don't let the heat get down in to the wedge area.

Another method is to drill and tap the end of the arbor, screw in a screw with an over size head and machine to length. I think this leaves the end of the arbor weak and is a LOT of work.

I prefer this easy method, make a spacer that fits in the barrel shroud hole the needed length. Some guys use tiny flat washers. You can get very small, stainless AN washers that fit very close. You may need to file/sand one or more washer to get the right fit. I just turn a steel plug from some drill rod on my lathe.

Some guys have used JB weld, sort of like bedding. It's messy, and I don't think it's strong enough when it's that thin, but it's better than a short arbor and needing to dink with how far you insert the wedge.

Next step is dealing with barrel gap. To much gap you can shorten the frame or barrel shroud, depending on what revolver you have. The 60 and 61 it's easy to shorten the barrel shroud, the other the frame.
After I did my first one I kicked myself for not seeing this sooner. Sure makes a difference on how well they go back together. Then you just need thumb pressure to insert the wedge.

 

[AdmiralB]

Part of that article I don't get - it claims that the gap at the forcing cone is often pie-shaped on Ubertis, because of the (again often) too-short arbor.

That suggests that the bottom of the barrel pivots on the frame, and the wedge pulls the barrel in on the arbor - so the barrel tends to point upwards and the 'crust' end of the pie-shape is close to the arbor, tapering up as you get to the top of the barrel.

Well, most of my Ubertis have a slightly pie-shaped gap, but it's in the opposite direction - thick at the top of the barrel, tapering as you move towards the arbor.

 

[madcratebuilder]

I'm sure other have different techniques that work very well, but this is how I approach it.

Short arbor allows the barrel to pull in at the top and a long arbor can allow it to pull in at the frame. The wedge and wedge slot can have some effect on this.

The first thing I do is get the barrel center line and the arbor center line perpendicular. Easier to spell than do.

I mount the revolver in a padded vise with the cylinder removed. Make sure there are no burrs on the arbor, then use a magnetic bubble level to level the arbor, than move it to the barrel and check if it's level. This is assuming that the bore is perpendicular to the outside hex of the barrel, usually not, but close enough for the girls I know. If it really bad, put a rod in the bore.

You want the arbor to bottom out and have 1-2 thousandth clearance at the frame/barrel shroud seam. Then look at the barrel gap. If it's tight you re-face the forcing cone. If it's excessive you shorten both the arbor and the frame or barrel shroud the same amount.

It seems about half of my c&ber's have a face on the forcing cone that is not 90* to the bore, so that may be part of your problem to.

You can set the gun up with out the arbor solid against the frame, but I think it shoots better if you do. You should have no wedge issues either. Once the wedge is properly fit and everything is tight there should be no movement when you fire to deform the wedge or knock it loose.