Take a pencil and mark both of your pins. Make the mark go from the center of the pin to the 12 o'clock position (it should look like hands on an analog watch when it's 12 noon). And continue the mark onto the receiver.

This is an index point to see how each of the pins move.

Ensuring your carbine is a complete safe firearm. Turn the carbine on it's side so you can watch the pins. Press the trigger and let the hammer drop. Keeping your finger on the trigger pull the charging handle to the rear and reset the hammer. Keeping your finger on the trigger ride the trigger forward until you hear a click. Keeping an eye on the trigger and hammer pin and keeping your finger on the trigger repeat the drill several times.

You will see that the front pin moves first clockwise and then counter clockwise and after about 6 or so trigger pulls it will complete one revolution. The rear pin also moves but not as much as the front.

The receiver is aluminum, the trigger and hammer pins are steel. After thousands upon thousands of trigger pulls (live or dry fire) the pins may have the ability to wear on the receiver and enlarge the holes in the receiver. When this happens, often times you will get pins that walk out during recoil. Also consider that not all manufacturers get the hammer / trigger pin holes in the receiver to an exact size, which may also allow the pins to walk under recoil.

The KNS pins are "anti-rotational", thus they don't rotate or turn like factory pins.

Are the KNS pins *needed*, for most probably not. Are they a way to protect your investment, in my mind yes.

Another added benefit to the KNS pins is I notice that the makes the trigger a little more crisp. It's a slight change, but noticeable if you are familiar with the way your current trigger brakes.

Many guys on the internet love to argue weather or not the KNS pins are worth while. I can't give you a scientific answer if they are or not, but if they didn't do anything over the long term, I wasted $25. If they worked I protected my investment.