80% is mainly for PDW suppressed: 5.5 barrel 80° #28W/suppressor LP Standard for years for when should I change the locking piece? MP5K (and clone variant) when suppressed MP5 or MP5K when every other aspect is at the recommended specification (bolt gap, clean gun with proper ammunition) When you are using proper ammunition, your gun parts are within specification, your bolt gap is good…(0.018) but you experience the following conditions: excessive recoil increased buffer wear/imprinting roller dents in the rails That is when you change your locking piece!
