I have not been in the AR game long enough to know what wears out the most ,but I always have these things along with tools cleaning kit and lube with me when Im out with my AR
http://palmettostatearmory.com/index...rol-group.html
http://palmettostatearmory.com/index...rer-s-kit.html
http://palmettostatearmory.com/index...epair-kit.html
These were out of stock when I posted this but they stock them often and they sell out faster you got to keep checking back and they will be back in stock
