KNS Hammer and Trigger Pin 2nd Generation Non Rotating AR-15 Small Pin Oversize .1555" Stainless Steel

AR-15 shooters who run suppressed uppers, 9mm conversions, or shoot high-round-count strings know the frustration: hammer and trigger pins that rotate under recoil, eating into your receiver and degrading trigger control. The KNS Precision Gen 2 Non-Rotating AR-15 Hammer & Trigger Pin Set eliminates that problem with a stainless steel anti-rotation system designed to lock pins solid and protect your receiver from damage—especially critical if you're running a valuable pre-ban or M16 receiver.

This oversized .1555" small-pin set uses a notched hammer pin that locks directly into the anti-rotation links, while the trigger is secured with locking screws. The anti-rotation links mount on the outside of the receiver, giving you a mechanical system that truly prevents all rotational movement. Both pins are CNC-machined and centerless ground for consistency, then heat-treated to handle the extra force that comes with suppressed fire and caliber conversions. The oversized diameter also tightens up trigger slack—a real benefit if your receiver has any wear or if you're looking to sharpen trigger feel on a new build.

Installation of oversized pins does require the use of a 3.95mm reamer (sold separately) to fit your receiver's pin holes. The pin set includes lube ports to keep your trigger group properly lubricated and running smooth. If you're serious about protecting a quality receiver and keeping your trigger control predictable under real shooting conditions, this is the kind of small detail that pays off over thousands of rounds.

Key Features

• Stainless steel construction for durability and corrosion resistance
• Anti-rotation links mounted outside receiver eliminate pin rotation under recoil
• Notched hammer pin locks into anti-rotation link slots for secure engagement
• Locking screws secure the trigger pin for added safety and stability
• CNC-machined and centerless ground for precision uniformity
• Heat-treated for strength under suppressed and conversion-load conditions
• Oversized .1555" diameter tightens trigger slack in worn or new receivers
• Integrated lube ports maintain proper trigger group lubrication

Specifications

Frequently Asked Questions

Will oversized pins work in my stock AR-15 receiver?

Oversized pins require receiver modification using a 3.95mm reamer (sold separately) to fit properly. Standard-sized pins (.154") drop in without modification, but this product is the oversized .1555" variant, so you'll need the reamer if your receiver hasn't been pre-reamed.

Do these pins work with suppressed uppers and 9mm conversions?

Yes. The Gen 2 design with anti-rotation links is specifically engineered to withstand the additional force exerted by suppressed .223 uppers and 9mm conversion setups, which generate more bolt carrier movement and can spin standard pins.

Will these pins protect my valuable M16 or pre-ban receiver?

That's a primary reason for using anti-rotation pins. Standard rotating pins wear holes in receivers over time. These pins lock solid with external anti-rotation links, preventing that damage—especially important if you're running a collectible or hard-to-replace receiver.

What's included in the pin set?

The set includes the redesigned hammer pin, trigger pin, anti-rotation links, and locking screws. It does not include the 3.95mm reamer, which must be purchased separately if your receiver requires reaming for the oversized pins.