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.
KNS Precision 0.154 In BLK SS Trigger/Hammer Pins
Titanium AR Anti-Walk Hammer & Trigger Pin Set
Titanium AR Anti-Walk Hammer & Trigger Pin Set
KNS Anti-Walk Hammer Trigger Pin Gen ST Non Rotating AR-15, LR-308
Rise Armament Blitz Elite Performance AR-15 Trigger w/ Anti-Walk
Guntec USA AR-15 Complete Anti-Rotation Trigger/Hammer Pin Set
MMC Combos AR 15 Trigger Upgrade Kit Including Davidson SKU: CO-82404
KNS AR-15/ AR-10 Gen 2 Mod 2 Stainless Steel Barbell-Style Anti
James Madison Tactical Black Ops Evo Single Stage Trigger
KNS Precision .154 Non-Rotate Trigger / Hammer Pin MOD ST
KNS Precision AR-15/M16/AR10 Gen ST Non-Rotate Trigger/Hammer Pins
A&A Anti-Rotation Pin Set - Red