[po18guy]

Roll the brass on a table to ascertain that the primer pockets are concentric. As to timing, it is easy to check on an unloaded gun. Either SA or DA, pull the trigger back and hold tension on it. There should be zero rotational play in the cylinder. Now, ease the trigger forward 1/8" or so and you should have a touch of rotational play - about like non-Colt revolvers normally do. Pull the trigger back again and you should be able to watch the hand rotate the cylinder a few thousandths into exact alignment with the barrel. They are tuned and timed so that when the trigger is all the way back, the hand pre-loads the cylinder against the bolt, and the bolt against the left edge of its window in the frame. If it does that on all six chambers, the timing is good.

 

[po18guy]

These we all double action shots?

 

[po18guy]

The reason I asked was that it is technically possible, in double action, for the hammer to drop before the trigger is all the way to the rear. "If" this occurred, you might have some off-center strikes. But, this also has to do with the alignment of the firing pin with the chambers, the diameter of the chambers and the fit of the unfired rounds. They must be smaller than the chamber, and so will settle to the bottom of each chamber when they are in firing position.

Truthfully, if timing is good and you experience no misfires, this is largely academic.

 

[po18guy]

If one must be absolutely certain, Brownell's sells ranging rods to check cylinder-barrel alignment. If the gun were shot from a fixed rest, its accuracy would undoubtedly be surprising. Colt's would not have released it with something as obvious to them as ranging problems. Knowing how precise they are, but being unfamiliar with the fitting/tuning procedure, I cannot imagine a Python being assembled without the use of a ranging rod.