This will take a little time, but worth the effort and easy to do. Unload your rifle and separate the upper and lower.

Next wiggle the selector switch and see if it is a tight fit into the lower. Should have zero slop. Check if the pistol grip is tight.

Next retighten the pistol grip screw. Sometimes they appear tight, but are not quite. Is the pistol grip even and tight?

The selector spring is held in place by a hole in the pistol grip. This spring is rather heavy and large in diameter than others.

Next cock the hammer (don't let it drop) and pull the trigger with the selector on "safe". Should be very very little creep.

If still loose, pull the pistol grip (again) and see if the selector detent is pointed up. Is the spring too long and coil bound?

Is the spring tooss short and not applying enough pressure against the detent, then against the selector? Finally...

...pull the selector (should come out easily) and eyeball the detent and selector detent and see if they line up properly.

Sometimes (rarely) a take down detent spring gets mistaken for a selector detent spring. Such will give a loose selector.

The final cure is a proper selector detent, spring and a tightened pistol grip screw using a lock or flat washer under the screw.

HB of CJ (old coot) (hundreds of builds)

 

well, i took it apart again, and all looked normal. i did tighten down the pistol grip screw and there was already a washer underneath the screw. there's still a little bit a play in the selector switch but it does have a good stiff click between safe and fire. that little bit of play might be normal i'm guessing.

 

my guess is it has the wrong spring.

did you put it together or buy it complete?

if you can measure the spring (length and diameter if possible)
knowing the exact dimensions of your spring will help us diagnose the problem, and narrow down if its the spring or the detent or something else.

 

My guess is that the part of the trigger bar that engages the safety doesn't correctly engage the safety. The tiny spring and detent don't provide for the "friction" of the safety fit. They only provide for a positive "click".

 

Yep...like already said sooss well, it almost sounds like you have a take down pin detent spring installed instead of the proper selector detent spring.

The proper spring is heavier and longer and is a snug fit into both the pistol grip and the hole in the lower. In this location, a heavier spring is needed.

We still need more info. Did you do your own build, or did some one else or did you buy the M4 complete from the factory? Sometimes kits are incomplete.

And...never start a paragraph with a conjunction. No, wait...sometimes the wrong springs are in the build kits. What you need is the proper spring.

Also... do you have a new selector? (safety) The tiny detent can be either silver or brass colored and must correctly fit into the notches on the safety.

Sounds like either the problem is the wrong spring....OR the detent does NOT fit snugly and correctly into the appropriate knotches on the safety.

Finally again, and this may be related to your problem, when squeezed on "SAFE", the trigger must have very little or no creep. HB of CJ (old coot)

 

i bought the rifle complete. its a colt. i'll probly just take it to a gun smith and let him look at it and see if it has the correct spring.

 

i bought the rifle complete. its a colt. i'll probly just take it to a gun smith and let him look at it and see if it has the correct spring.

I mean this as encouragement, not as criticism, so please don't take this as criticism. One of the great features of "modular" firearms, such as Glocks and ARs, is that you rarely need the services of a gunsmith.

The AR is a particularly simple machine. There are plenty of guys on this forum who could walk you through what you need to do to get it going. Even a Colt :-? could have the wrong spring installed.

Good luck on the fix. Whatever's wrong is something REALLY simple! ;-)

 

hey, i appreciate all the advice fellas.