M16 9mm issues light primer and hammer

[y2k87k2000]

I have a registered m16 receiver in 9mm that had minimal issues up until 2 months ago. I have owned it for about 6 years now. The buffer detent has broken 3 times while shooting, light primer strikes and not charging the hammer/loading the next round. The bolt and buffer weight are the heavy ones by m60joe.

It happens in full and semi. I have replaced the hammer spring with probably a mil spec spring and the disconnector.

Any thoughts?

 

[TheColtCollector]

I thought extra power hammer springs were the standard when playing around with 9mm in the ar platform

 

[chili17]

Look at the bolt and see where the buffer detent it hitting it. My guess would be the front (towards the firing pin) might try a new recoil spring or drop a $1 in quarters down the buffer tube to short stroke the bolt a bit

Also sounds like you have hammer follow. New hammer and disconnector?

 

[sniperdoc]

1) Stronger Buffer Spring (or 4 Quarters, as Chili suggested, &
2) EP Hammer Spring, as Colt suggested
3) Check ammo; maybe what you're using now has harder primers vs what you were using?

 

[y2k87k2000]

I checked where the bolt was seated, about 1/8 inch forward from the buffer and from the rear of the upper receiver and that explains the light primer strikes. Stripped it down and found the barrel ring was too small from the locking ring and it was truly a free floating barrel. I am awaiting the xp springs before I try shooting again.

I only replaced the disconnector, disconnector spring and hammer spring. I was shooting a little bit of WWB, Remington umc and Magtech ammo so nothing new for me.

Still y'all have been a huge help!

 

[chili17]

I checked where the bolt was seated, about 1/8 inch forward from the buffer and from the rear of the upper receiver and that explains the light primer strikes. Stripped it down and found the barrel ring was too small from the locking ring and it was truly a free floating barrel. I am awaiting the xp springs before I try shooting again.

I only replaced the disconnector, disconnector spring and hammer spring. I was shooting a little bit of WWB, Remington umc and Magtech ammo so nothing new for me.

Still y'all have been a huge help!

Yea, I would say you found the problem

 

[DINK]

There were some very early 9mm barrels made that had the "ring" too small and there was a specific washer available to solve that problem. I had to get one from Colt, but that was a long time ago. If you need one, I can ask a buddy there if one might be kicking around.