You need to check B/C gap, end shake, and cylinder face square (all in one measurement).
Get some car feeler gauges and measure the gap between the cylinder and forcing cone AT EVERY CYLINDER HOLE. Then, repeat except apply rearward pressure on the cyliner to get the maximum gap. The difference in the gap with the cylinder fully forward and pulled to the rear is the endshake.
Endshake on a new gun should be 000 - .001". B/C gap should be between .004" and .007" (service limit .010"). The B/C gap should not vary more than .001" all the way around the face of the cylinder as it is turned.
If this is a Titanium cylinder, it swells considerably when it gets hot.