I think it would fall under "secondary compentents" for 15000 rounds min. before failure.(Swiss Arms test documentation)
"2.- Weapon service life
2.1 Service life of individual components
The service life or individual components is classified into 4 groups as follows:
a) min. 10000 rounds for wearing parts of the bolt assembly
b) min. 15000 rounds barrel life
c) min. 15000 rounds for all other secondary components
d) min. 30000 rounds for major components.
2.2 Extended service life / Functional safety
- Experience indicates that depending on the grade of ammunition used, the barrel has to be changed after approx. 20000 up to 30000 rounds have been fired.
-15000 rounds for wearing parts of the bolt assembly are quite feasible: other small components will last for anything up to 30000 rounds.
-Major components such as trigger housing, bolt, receiver, plastic parts, the main components of the trigger action may readily be expected to withstand 40000 rounds.
-We have weapons at our plant which have major components still fully functional after firing 80000 up to 100000 rounds."