The Python doesn't wear as fast as the internet would have you think.
Most Colt wear is due to abusive treatment like shooting double action as hard and fast as you can jerk the trigger, or "force cocking" in single action by yanking the hammer back hard.
Normal wear parts are the hand and the bolt.
I'd also recommend a firing pin and spring.
Here's sources for Python Parts:www.e-gunparts.com/productschem.asp?chrMasterModel=0660zPYTHONwww.brownells.com/aspx/ns/schematics/schemmfg.aspx?schemid=149&m=3&mn=Colt%c2%ae&model=Python+www.jackfirstgun.com/
(One of the best, but you have to CALL).www.parts4guns.com/
(Click on COLT, and WAIT, it's slow).armattweb.com/gunparts/
For a good read on the truth about the Colt action, here's an article by one of the few Colt experts still working:www.grantcunningham.com/blog_files/colt_python_delicate.html
Here's my instructions on how to check your Colt for proper timing and operation:
BOLT RETRACTION AND "SNAP BACK".
Open the cylinder and look at the small "lug" in the bottom of the cylinder window. This is the cylinder locking bolt.
Cock the hammer, and watch as the bolt retracts into the frame and pops back out.
The bolt MUST begin to retract THE INSTANT the hammer begins to move.
There MUST be NO (ZERO) hammer movement possible before the bolt starts to retract.
The bolt should retract smoothly with no hesitation until it's fully retracted, then it MUST pop back out with a clean "snap".
There should be no hesitation, and no amount of "creeping" back out.
Close the cylinder.
Use your left thumb or fore finger to again cock the hammer, closely watching the cylinder bolt as you SLOWLY cock the hammer.
As the hammer comes back, the bolt will retract away from the cylinder.
The bolt MUST retract far enough to unlock the cylinder BEFORE the cylinder begins to rotate.
If the bolt is still slightly engaged with the cylinder lock notch, the cylinder will be attempting to turn while still partially locked.
This produces a "catch" or "hard spot" in the trigger pull and will damage both the bolt and the cylinder lock notches.
This often appears as metal "pulled out" of the lock notches, with rounded off and burred notches.
BOLT DROP TIMING.
Continue to cock the hammer, LIGHTLY laying your right index finger on the cylinder just enough to prevent "free wheeling".
Watch for the bolt to drop back onto the cylinder. WHERE the bolt drops is CRITICAL.
The bolt MUST drop onto the leade or ramp in front of the actual cylinder notch.
If the bolt drops too soon, (in front of the notch ramp), it will mar the finish of the cylinder.
The bolt SHOULD drop into “about” the MIDDLE of the ramp.
If the bolt drops late, (farther toward the actual locking notch) the revolver may display "cylinder throw-by".
In this condition, during double action shooting the cylinder may rotate PAST the locking notch, and fire in an unlocked condition.
It's the nature of the Colt action, that a hesitant or jerky trigger pull by the user can induce throw-by in even a properly tuned Colt.
The Colt trigger should be pulled with a smooth, even pull, with no sudden jerks at the beginning.
Continue to pull the hammer back and both watch and listen for the bolt to drop into the cylinder lock notch.
The bolt MUST drop into the actual lock notch BEFORE the hammer reaches full cock.
The most common Colt mis-time situation is the hammer cocks before the bolt drops into the lock notch. (Hammer is cocked, but cylinder isn't locked).
In this condition, with the hammer fully cocked, you can push the cylinder slightly, and you will hear the "CLICK" as the bolt drops into lock.
In my experience, most Colt's leave the factory with the bolt dropping a little late into the leade, but usually wear in to correct timing.
If the bolt drops onto the cylinder early, no real problem, but there will be extra finish wear.
If the bolt drops late (closer to the lock notch) the cylinder may "throw by" or rotate TOO far in double action and this can cause off-center primer hits and firing while unlocked.
Each of these checks should be done on EACH chamber. All of these checks are better done individually. In other words, do the bolt retraction check on all six chambers, then do the bolt drop test, and so on.
A properly tuned Colt will:
Have a smoothly functioning bolt with no sticky or hesitant movement.
Unlock before the cylinder begins to turn.
The bolt will drop onto the middle of the ramp.
The bolt will drop into the lock notch before the hammer reaches full cock.
Have a smooth trigger pull, which does "stack" or get heavier as the trigger is pulled.
You can also check for "End Shake" which is back and forth movement of the cylinder in the frame.
Push the cylinder to the rear and hold it there while you use an auto feeler gage to gage the barrel/cylinder gap.
Push the cylinder forward and hold it there while you again gage the gap.
Subtract one measurement from another and that's how, much if any, end shake it has.
The specs are:
A maximum of 0.003"
If it's over that, the gun must be sent in to Colt for repair.
WARNING: Local gunsmiths do not have the special tool needed to stretch the cylinder collar to correct excess end shake. Only Colt can do it.
Shooting the gun with excess end shake will ruin the gun. The loose cylinder banging back and forth will hammer the gun and ruin it.
Minimum of 0.004"
Maximum of 0.008".
"Perfect is 0.005".
The actual barrel cylinder gap is with the cylinder to the rear.
Enjoy, you now own the finest production double action revolver ever made.
It was literally hand assembled, and each part was hand stoned and filed to a perfect fit, then polished and tuned.
It's a true semi-custom gun, which is why they cost so much.
IM/email ARFCOM member dfariswheel. He is a real expert on Colt guns.
In a past post he has suggested how to check /measure if a Python needs to be "service" by cylinder end shake etc.
According to dfariswheel, all of the parts of a Python are hand fitted to particular gun and are not interchangeable.
But I would contact him for the final word.
Revolvers are "different" from autos.
Most auto parts can be installed with little or no fitting.
Almost all revolver parts are individually fitted at the factory and will NOT 'drop in".
This is especially true of the older Colt action.
These are complicated actions with tiny working surfaces. The design is NOT "Intuitive" and what appears to be going on is NOT what's happening.
Colt parts require the services of a Master fitter to install, so if you need parts installed, Colt, Cylinder & Slide or Cunningham can do it, IF you have the NEW parts.