Sear Issue

[rocky321]

I replaced the trigger on my M2 for appearance purposes only, and now the sear won't engage the hammer securely. The triggers are identical except for the finish. If I remove the hammer spring and plunger, the sear will grab the hammer securely. I put back the old trigger, and I'm having the same issue. What happen here? BTW, what is the lenght of the sear spring? I may have confused it with another spring.

Information

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[CrossedCannons]

what is the lenght of the sear spring?

free length = 0.687"

[rocky321]

free length = 0.687"

Thats what I have in there!!??

[Tired Retired]

Rocky,

Check the trigger spring. If it is not pushing "down" on the rear of the trigger strong enough, the trigger will not reset completely and rotate "clear" to allow the sear to engage the shelf on the hammer.

Sometimes I have accidently "bent" the trigger spring a bit too "closed". You may have to bend it back "open" before you re-insert it into the trigger housing body.

Just a suggestion...

[rocky321]

Replaced with a new spring. Same issue.

[imarangemaster]

If the carbine is an M2 as you say, the M2 sear and the full auto disconnector block have critical tolerances on the top sharp corner only on M2 sear. Several I had to do fitting so the would fire reliably on full auto. One it interfered with semi auto too, if I remember right.

[rocky321]

Would a bad/wrong sear spring cause the same problem? As I said, I did mix up the spring with others.

[imarangemaster]

Possible. The reset is dependent on spring compression and release. Maybe the edges of the sear binding up with the sides of the trigger? Maybe the spring is seating too deeply on the new trigger.

[rocky321]

Possible. The reset is dependent on spring compression and release. Maybe the edges of the sear binding up with the sides of the trigger? Maybe the spring is seating too deeply on the new trigger.

Sear binding up makes sense because I don't see the same movement as I do on my M1 trigger assembly. Emery cloth to the sides of the new trigger?

[imarangemaster]

Can't hurt to do the sides of the sear and inside if the trigger. Heavy parkerizing I have seen on some M2 replacement parts are pretty coarse. Polish and lube. If it is still a problem, replace the auto disconnector block with a small washer to space the hammer. Try it then. If it works only if the disconnector is out, the disconnector fit is a problem. Try it, and PM me if it doesn't work. I have some other thoughts.

I've worked on M2s for the PD where I was an armorer back in the day. SOme you just dropped the parts in, some needed tweaking.

PS: I also went through two M2s a Class III dealer in Southern Illinois had that weren't working right and fixed them. That was about 2 or 3 years ago.