Measuring cylinder gap

[Wfevans4]

When you measure cylinder gap, do you apply backward pressure (pulling it backwards) to the cylinder when you insert the feeler gauge?

 

[Alk8944]

When you measure cylinder gap, do you apply backward pressure (pulling it backwards) to the cylinder when you insert the feeler gauge?

The cylinder should be pulled to the rear. Once you have that figure then push the cylinder forward and re-check the gap. The difference between the two numbers is the end-shake. which should be no more than .002".

 

[stansdds]

Measuring with the cylinder pushed forward and backward will give you some very critical information. With the cylinder forward, you measure the barrel-cylinder gap, this will be the available clearance when the firing pin impacts the primer and forces the shell and cylinder forward. 0.003" is considered minimum, the maximum allowable has varied, but 0.006" is considered ideal for most applications, 0.010" is the current S&W maximum.

Measure again with the cylinder pushed back, then subtract the barrel-cylinder gap measurement. This gives you the amount of the cylinder's end shake. 0.001" is the bare minimum for reliable cylinder function, 0.002"-0.006" is the current S&W acceptable standard.

 

[gwpercle]

When you are doing all this pushing and pulling and measuring ...
It helps if you have ... Three Hands !
Gary

 

[stansdds]

There is a little skill in holding the revolver, pushing or pulling on the cylinder, all while inserting a feeler gauge. You learn this skill real fast when you own a Dan Wesson revolver that has interchangeable barrels.

 

[Hapworth]

My understanding has always been B-C gap is measured holding the cylinder rearward, so as to know the greatest amount of gap the revolver will have under ignition, which itself pushes the cylinder first rearward.