[ambler1]

Took my 556 out last Saturday. I have about 300 rounds in her and so far so good. Back home while I was cleaning it, I noticed that the spring on the firing pin became kind of loose and it extended forward and covered the recess on the firing pin (the other end of the spring is still attached to the end of the firing pin). I did the functional check and everything seemed normal. Is it normal that the spring would come "loose", or is it something to worry about? Your input is appreciated.

 

[ullie]

...it happens sometimes..it's nothing to worry about...sometimes the spring will jump the shoulder (the hump) in front of the firing pin stud cutout...when installing the firing pin spring onto the firing pin...you can install it so that the two coils of the firing pin spring are to the rear of the firing pin and the three coils pressing against the shoulder (hump) before the cutout...the firing pin spring "must" be at the rear of the firing pin...between the rear shoulder and the shoulder ( hump) before the cutout for the firing pin stud...

...the firing pin tunnel in the bolt shaft should have two demensional diameters...actually three......after traveling about 20mm from the rear it narrows so that the firing pin spring cannot further enter the tunnel...preventing it from entering the firing pin stud cutout..this can be easily seen when you push the firing pin and spring into the tunnel...you will meet resistance and the spring will compress as you push it further in...you can also see what appears to be a concentric ring when shining a flashlight through the "firing pin hole" in the bolt face...

...you can roughly check this by inserting the firing pin with the spring installed several times into the tunnel...just push it in and allow it to spring back......the spring should start to compress when it is about two thirds into the tunnel...

 

[ambler1]

thanks ullie.