...The only thing I don't like about the AR 556 is the trigger. It has a lot of creep and feels like it has sand in it,so I want to change it...
The AR trigger is intentionally designed with a long sear engagement to prevent unintended discharges from rough handling and potential doubling. The difference between a single stage AR trigger and a two stage AR trigger is the weight of the creep. In a single stage trigger, the pull weight is the same from the beginning all the way until the sear breaks and drops the hammer. With a two stage trigger, the initial travel (first stage) is light until just before the sear breaks. At this point, the two stage trigger has a sharp increase in pull weight. Many describe it as running into a wall. The pull weight increases at this point and travel to sear break is short. Compared to a single stage, the break feels like there is little to no creep.
There is little you can do about the creep in the factory trigger (at least not without compromising the safety of the trigger). But there is something very simple you can do about the four and a half loads of sand and gravel that comes with most standard AR triggers, from the comfort of your living room couch.
Separate your AR into its two halves. Cock the hammer and firmly grasp it between finger and thumb. Push forward a little bit, then press the trigger. Do this a few times, then check to see how the trigger feels. If it's still gritty, do it again. Once the trigger gets smoothed out, remove the trigger group from the lower and clean it thoroughly. Lubricate the sears, the bottom of the hammer and the pin holes with clean grease (just about any good grease will do) and re-assemble. Test the trigger for feel and function. The trigger should be significantly smoother. If it's still a bit gritty, you can continue working with it to smooth out the pull even more. This won't fix the creep, but smoothing out the pull will give you trigger that will be the same every time.
Be careful! Don't let the hammer fall against the lower as it will cause damage. Keep the hammer pinched between your finger and thumb while working and testing. A thick piece of leather, rubber, nylon etc. can be placed between the hammer & the lower to protect the lower from damage.
Don't over do it! Too much pressure against the hammer can damage the sear. Be patient. Do a little at a time and test the pull frequently. You'll soon develop a feel for it and it won't be long before you notice an improvement.
Do not succumb to the temptation to take a set of stones to your AR trigger to smooth it out. AR triggers are case hardened and the depth of the hardened steel varies from trigger to trigger. It's all too easy to cut through the case hardening and expose the soft material underneath. Once that happens, the trigger group will wear quickly and will soon start doubling. There are those that have stoned or polished their AR triggers successfully, but there are just as many who cut too deep.
Once you've smoothed out your trigger, go shoot the rifle. One reason new AR owners find the dizzying array of trigger choices confusing is lack of experience. The more trigger time you have, the easier it will be to start sorting out the various triggers and figure out which one you want. Or that the factory trigger now works just fine for you.
Whatever you decide, clean and grease up your trigger. Even the most refined Geissele trigger will be gritty without lube.
