Receiver Play or Slop

Many owners of the AR180B will notice that the upper and lower receivers have a little bit of play between the two. Armalite claims that this has no adverse effect on accuracy but many owners still find it less than satisfactory. A simple fix is to take a pair of vise grip pliers and bend the ends of the upper receiver together so that they more tightly hold the guide rod assembly. When making this modification be sure you just bend a little bit at a time and don't make it sit too tight. Also try to keep everything as centered as possible.

Firing Pin Jamming

In the first month I had my rifle I was rather lazy and never disassembled the bolt for cleaning. When I finally decided to strip it down I noticed that the firing pin would not come out when the retaining pin was removed. I looked the bolt over and noticed that the area where the hammer strikes had become worn. It seems that the hammer had caused the edges of the hole where the firing pin sits to squish inwards, thus making the hole to small for the firing pin to come out. I simply took my Dremel and chamfered the edge of the hole. Problem solved.

Front Sight/Gas-block Adjustment

The AR180B has a front sight/gas-block that can easily be adjusted side to side for windage, thus allowing the rear sight to be centered in the housing. For ease of initial adjustment one will notice there is a dimple punched in the front of the gas-block that marks the center. This dimple can be used to line the gas-block up with a slight line that marks the top center of the barrel.