Again, HOLDING THE TRIGGER BACK IS NOT A VALID TEST FOR ANYTHING ON ANY REVOLVERS EXCEPT THE OLDER COLT'S.
Almost all revolvers are locked up by the SIDE of the hand that rotates the cylinder pressing on the ejector ratchet.
When the action is cocked the top of the hand starts the cylinder rotating, but immediately bypasses the ejector ratchet and it's the SIDE of the hand that pushes the cylinder the rest of the way.
Once the hammer is just cocked, that's as tight as the cylinder is capable of locking.
Holding the trigger back cannot lock it any tighter since the side of the hand just slides past the ratchet.
No matter HOW hard you pull the trigger, the cylinder can't lock any tighter.
Again, no matter how tight it SEEMS to be locked, there's enough backlash designed into the action to allow the cylinder to move enough to align the chamber with the bore.
Only the older Colt's like the Python action locks up tight with the trigger pulled.
In the old Colt's the TOP of the hand pushes against the ejector ratchet to force the cylinder into tight Colt's "Bank Vault" lockup.
The harder you pull the trigger (within reason, you can damage it) the harder the hand pushes against the ratchet and the tighter the cylinder locks.
In guns like the S&W, Ruger, Dan Wesson and newer models of Colt's if the action is out of time and the cylinder isn't locking fully, you fit a WIDER hand.
In the old Colt's like the Python, if the action is out of time and the cylinder isn't locking fully, you either stretch the hand or fit a new LONGER hand.