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Author Topic: Shimmage  (Read 3524 times)

Offline oldfart

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Shimmage
« on: March 23, 2017, 05:01:28 AM »
OK so I'm looking for info on tweaking my Paterson,
measured the barrel on the frame---1.681
measured the barrel over the frame-1.542

this gives me a shim depth of .139
Do i go a tad under on the shim? or no?

anyone totally strip the innards out for a clean up? or tweaking like we do to other colts?
any warnings? things NOT to do? to good to do?

Offline ssb73q

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Re: Shimmage
« Reply #1 on: March 23, 2017, 05:47:45 AM »
Hi old, a 0.139" shim IMO is much too long for a Pietta arbor extension. You may find ~0.080" about right. At first I made the extension for too narrow a barrel/cylinder gap where fouling hung up the cylinder on the first shot. I now have a gap of 0.006" on my Petta Paterson. You may want to visit this thread from this message down:
http://blackpowdersmoke.com/colt/index.php?topic=2178.msg21655#msg21655

Be careful you have detailed instructions on disassembly and reassembly of the Paterson. I found this very useful reference:
https://www.amazon.com/gp/product/0873497678/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

The Paterson is much more complex to disassemble and reassemble than the other Colt models. There are so many pieces that are just held together with screws that changes barrel registration each time the Paterson is taken apart.

I now just remove the grips and barrel for cleaning in soapy water, then drying in an oven at 250 degrees for 1/2 hour to completely remove all water. Then squirt Ballistol in the action to lube the internals. Colt designed the mechanism of the Paterson with the help from the devil. IMO shoot it a lot, but disassemble little.

Regards,
Richard
There’s nothing better in the morning than the smell of bacon and black powder smoke!

Offline oldfart

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Re: Shimmage
« Reply #2 on: March 23, 2017, 06:29:07 AM »
richard, did Pietta make the arbor "short" by 1/8th only in 2015 ?
(reading what you posted on the other tread  reply #28)  if so it would date my Paterson

I was assuming from what I've read on shimming the arbor on the other colts (ubertie,especially ) that you shimmed it so i will not tilt the barrel into the cylinder

you wrote that you shimmed yours to a .006 gap

to do that on mine id need a shim of  .139 + .006 = .145 shim thickness
so I'm confused on your .080

is the trigger supposed to flip down AND up on its own? mine flips down when cocking but not up,,

does your barrel just above the two small "pin" holes have another hole 3/16diam and below the arbor hole? mine does, (imagining alignment pin hole?)

Im still trying to confirm its a pietta, as its either been defarbed  as it has no markings anywhere except the proof on the cylender
« Last Edit: March 23, 2017, 06:30:39 AM by oldfart »

Offline ssb73q

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Re: Shimmage
« Reply #3 on: March 23, 2017, 07:15:14 AM »
Hi old, most Uberti Colt revolvers have too short an arbor that requires improvement. All current Pietta Colt revolver with the exception of the Paterson have a correct sized arbor. The Pietta Paterson arbor is too short. My Pietta needed a brass button shim of ~0.080".

The trigger on my Pietta Paterson drops down when cocking, but needs to be manually put back up after the hammer is down.

My Pietta Paterson has a shallow hole between the frame pin holes and arbor hole, 0.230" diameter. There is also a number stamped near the frame pins, 92.

Regards,
Richard
« Last Edit: March 23, 2017, 09:41:56 AM by ssb73q »
There’s nothing better in the morning than the smell of bacon and black powder smoke!

Offline oldfart

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Re: Shimmage
« Reply #4 on: March 23, 2017, 07:30:27 AM »
Thank you sir,

I've no numbers near the frame holes,,,,the mystery deepens

Offline ssb73q

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Re: Shimmage
« Reply #5 on: March 23, 2017, 09:51:49 AM »
Hi old, IMO you have either a Pietta prototype or defarbed Pietta Paterson. If a prototype, it may have some intrinsic value. I currently have three new mainsprings on back-order. Grinding down the mainspring will provide a better trigger pull on The Pietta Paterson. It will be interesting if I ever receive replacement mainsprings. IMO these Paterson replicas are on life support.

Regards,
Richard
There’s nothing better in the morning than the smell of bacon and black powder smoke!