AR Sponsor
Posted: 12/25/2013 6:17:50 PM EDT
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After feeling the side to side play on my AR trigger and hammer I decided to install shims to tighten things up. Shims were located online at various suppliers but at the cost of an arm and a leg. Being frugal I’m not going to pay around $15.00 for 10 or so .005” shim washers especially when .005” shim kits for the purpose would not work on a setup that required a .007” shim on each side of the trigger.
Having done lots of engine rebuilding in the past I ran across 2 well used sets of feeler gauges and removed the .007” and 006” gauges. On the bottom of each gauge is a mounting hole that was around the .156” diameter on my trusty JP Anti Walk pins. A heavy pair of scissors was used to cut off the mounting hole sections and the pieces were quickly nibbled away on a bench grinder until they were a slightly larger diameter than the coils on the hammer spring and the burred edges were sanded smooth. A test fit with no springs was done using the .007” shims on the trigger and .006” shims for the hammer and both were spot on. While the test setup was in the receiver a dab of fine valve grinding compound was placed on the hammer notch. Holding pressure against the hammer while pulling the trigger and repeating the process helps smooth factory roughness. Following disassembly a high speed buffing wheel helps to polish the trigger/hammer points of contact. An inverted drill bit or other pin with length can be used to help with assembly using the springs. The trigger and its shims are fairly easy to install. The hammer and shim alignment requires a few choice words but not excessive force. The results are a smoother, positive trigger that has two stage characteristics while retaining safety standards... When on the safety position a slow trigger pull should feel smooth and release should feel smooth. The feel will eventually change as the parts mate. At that point use swabs, alcohol to clean the hammer notch and apply a drop of Tetra, etc...While on safety pull the trigger until it stops travel and hold its position then switch the selector to fire to check break...Procedure also works well for shot placement. |
| It should be of no surprise that an issue M16 would be loose as a goose and still serve a purpose. On the other hand there should be no excuses for excessive slop being acceptable on an expensive AR 15 build unless the weapon is intended to be used in an environment where grit and grime enters the equation. |
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