Suppressors should last for a very long time. Some of the first generation of suppressors from a hundred years ago are still hanging around mostly functional, so we’re talking a while. The biggest threats to a suppressor’s lifespan are 1) heavy, sustained automatic fire and 2) improper installation. A sustained high rate of fire can do the same thing to a suppressor as it does to a barrel – heat it up to the point where it starts to melt or deform. Improper installation can cause the suppressor to not be perfectly aligned with the barrel. In that case, your suppressor’s lifespan may only be a single shot.