These AR15 anti walk / anti rotation hammer and trigger pins are what you need to keep your receiver from excessive wear and tear. Keeping the hammer and trigger pins from rotating is especially important when shooting full auto or with pistol caliber builds, such as 9mm AR15's.
Dirty Bird AR-15 Anti-Walk Pin Set - Black
AR-15 / AR-10 BURNT BRONZE CERAKOTE Anti Walk Hammer Trigger Pins
Titanium AR Anti-Walk Hammer & Trigger Pin Set
JP Enterprises Oversized Anti-Walk Hammer Trigger Pins AR-15 2PK
Rise Armament, Anti-Walk Trigger & Hammer Pins, AR15 & AR10 Compatible
PSA Custom Anti-Walk Trigger & Hammer Pins
AR-15AR-10 ANTI WALK TRIGGER PINS GOLD, CERAKOTE, .154, TRIGGER/HAMMER PINS
PIN SET, AR PLATFORM, HAMMER/TRIGGER, ANTI-WALK, BLACK
Grip/LPK Combo: Skeletonized Polymer Grip + Recoil Technologies AR15 Ejection Port Door + Recoil Technologies Anti-Walk AR15 Receiver Pins