Could someone comment on the subject of trigger and hammer pins?  There are a number of aftermarket products such as stainless pins, oversize pins, anti-walk pins, pins with set screws, etc.  Is trigger pin wear a big problem?  Any advantage in installing pins without detents and little circlips on either side of the lower?  Thanks!
-WF

The trigger hammer pins have two grooves in them.  The hammer has a J spring which engages the center groove and one of the hammer spring legs engages the outer groove of the trigger pin.  These pins are clearnce fit into the receiver and in spite of peoples concern, normally rotate when the trigger operates.

Properly installed, the standard GI pins are all you will ever need.  

I put together my kit (JT CAR upper and Eagle lower) and went out shootin'. I noticed after a while the trigger pin had backed out, which was odd since I thought the hammer spring was suppose to catch it.

Turns out I had installed the hammer spring backwards/upside down and the spring "legs" wasn't catching the groove in the trigger pin.

Something to check.