AR Sponsor
Posted: 11/1/2007 12:28:21 PM EDT
|
Hey all. Question on a new Bushmaster I have. It's got a 2-stage match trigger. I haven't fired it yet- just dry firing/playing with it at home until I get my ammo. The other night I think I noticed weird new behavior- the trigger, in its first stage, requires uneven pressure. Now, I don't know if this counts as trigger creep (first time owner here), and I also can't seem to recall if it always did this (always being the past 4 weeks). But it somehow felt different last night. As a further example, if I close the bolt and dry fire, and then pull it, it's a perfectly even pull. But that first dry fire will have an uneven first stage. So my questions are: is this normal? could something have changed while it's just sitting in the case? is there a way for me to adjust this? The only culprit I could think of is that it's gotten colder here recently and I haven't cleaned/oiled it since I got it. Thanks, BB |
Ya know, 'Trigger Creep' would make a great nom de net.  The weird thing about AR triggers IS their inconsistency. Mine will be great for a time, and then resume creeping. Two things to try/do. With a clear weapon and no mag, pull the trigger and hand cycle the bolt; keep the trigger pressed while you do this. Then release the trigger and squeeze off another dry snap. This is more like the trigger pull you will experience when you are actually shooting. See if the pull feels any better. Open the upper and find where the hammer and sear engage each other. It should be a shiny surface at the base of the hammer when the hammer is forward. (DO NOT let the hammer slam against the lower when the upper is open). Lube this spot. I like Gunslick anyhdrous graphite, but posters here have other preferences. After putting a good dab of Gunslick on the sear engagement, do a ton of dry snaps, making sure you don't let the hammer slam on an open lower. Shooting/dry snapping will eventually improve the trigger. I will never understand why ARs have such crappy triggers when the sear engagement is very direct. There is a fellow here who will likely pop up on this strand who reputedly does great AR triggerjobs. Sending your hammer/trigger to him is another option. Moon |
| Gritty or uneven take up on a two stage trigger is NOT creep. You have nothing to worry about. This can often be caused by the stock FCG pins rotating slightly or the fact that the pins and hammer/trigger interfaces have a rough contact surface between them and are not lubed. The take up on a two stage trigger is not important... the release is. |
|
Pretty simple really- imagine a trigger that has two stages of resistance. The first stage, which requires less resistance and is distance-wise about half the pull, gets you to the second stage, which requires more pressure before it fires. It's really useful for match competition and shooting accurately- you sight the target, pull till the second stage, really hone in, then click- let 'er go. Not so good for rapid fire or military- type applications, but extremely good for single shot accuracy. Another analogy? Think of a pickle jar where one twist is really easy and the next, which opens it, takes a bit more pressure 
|
| A trigger with a short, weighted take up is the simplest description. If the take up pull is 1 pound for take up and 3 pounds for the second stage you get a 4 pound trigger that releases like a 3 pound trigger. They usually have a complete lack of creep and offer better control for precision shooting. |
| My trigger had lots of take up and was gritty, I coated the bearing surfaces with a pumice paste for polish teeth and made about 350 trigger pulls, then took the trigger apart, cleaned it and reinstalled. feels like totally different trigger. I dont know why there is less travel in it and the pull weight is a full 1/2 LB heavier? What did I do that would cause there to be less travel in the first stage and the pull weight to increase? |
AR Sponsor