I've wondered about the durability of the buffer. Does anyone know:
-How many rounds one is expected to last?
-Is it necessary to have one in place for the rifle to function?
-Are they easy to replace if neccessary?
After Terra's reply:
-How would an out of spec chamber affect the life of the buffer?
I haven't spent any real time messing with the buffer in the XCR, but I have pressed it with my finger a couple times, and the material feels softer than, say, the polymer type semi-foggy nipple-thing on the rear of an AR15 buffer.