How to (correctly) measure barrel cylinder gap?

[ExMachina1]

Two-part question here:

1) Is "in spec" barrel/cylinder gap measured w/ no pressure on the cylinder or while the cylinder is pulled to the rear?

2) Is the "measured gap" the size of the largest feeler gauge that can be slid all the way through the gap or is going half-way enough to count? If it must go all the way, how easily should the gauge go through?

I'm may case, I can get a 0.008" gauge part of the way through but not all the way. The 0.006 goes all the way.

Thanks

 

[-db-]

It's measured with the cylinder to the rear. The feeler gauge should pass fully through the gap with slight friction. If there's no friction, try the next size wider, in your case a .007" gauge.

 

[ExMachina1]

Thanks -db-.

Fast reply and to the point!