Dorin PS90 Stainless Steel Upper Receiver Spring Set

The Dorin stainless spring set replaces the three primary upper-receiver springs in the PS90 with 17-7 stainless steel equivalents. The factory springs are functional but degrade over time and contribute to inconsistent cycling on high-round-count rifles. The Dorin set includes the barrel-support spring, the return spring, the charging spring, and a 15mm wrench needed for the upper receiver work.

For PS90 owners running thousands of rounds annually or maintaining older PS90s purchased used, this is a worthwhile preventive upgrade. 17-7 stainless steel resists fatigue better than the factory spring stock and stays at spec longer. The included 15mm wrench is a thoughtful inclusion since the tooling is otherwise specific to the PS90 and not common in most home armories.

Installation requires partial PS90 disassembly. Owners not comfortable with PS90 internals should pay an armorer to install rather than risk reassembly errors.