I need some help with my AR

[77bawls]

For the life of me I can't figure out what's wrong with it. It feeds fine and ejects fine, but once in a while I pull the trigger and it just clicks. I eject the round and it just has the floating firing pin mark on it. I did the 15 minute trigger job on it but the rounds that do go off have a deep primer strike, so I don't think it's because the hammer spring was cut.

[Ben Segrest]

simple test: Replace the hammer spring. See if it makes a difference.

[FlexCJ5]

Hammer follow or bolt bounce. Change out the fire control springs and maybe the buffer spring.

[Ben Segrest]

Originally Posted by FlexCJ5

Hammer follow or bolt bounce. Change out the fire control springs and maybe the buffer spring.

I ruled out hammer follow because he said he gets a click. It could be bolt bounce, but that's a little harder to diagnose.

[77bawls]

Hammer follow?

I thought that it wasn't in battery so I hit the forward assist before every round and it still had problems. I have another trigger group for it that I will try. It's not a milspec buffer tube or spring.

I would also open it up re-cock the hammer and it would fire so it is in battery.

Edit: I assume hammer follow is when it follows the carrier instead of catching the disconnector and sear. That's one thing I haven't checked. (Take a peak before every round.)

[aloharover]

You have the firing pin installed fully into the bolt prior to installing the cottor pin?

See if you can pull out the firing pin without removing the cotter.

If installed correctly I would suspect weak hammer spring

[77bawls]

Originally Posted by aloharover

You have the firing pin installed fully into the bolt prior to installing the cottor pin?

See if you can pull out the firing pin without removing the cotter.

Nope, the pin is installed correctly.

If installed correctly I would suspect weak hammer spring

That's the only thing I can think of too, but why would it not have a primer strike on some and deep on others?

.

[Unka-Boo]

Have you lightened the hammer at all? I've had some that worked with the stock weight hammer and others that needed the hammer lightened a bit to work right ( shaving the tail off )

As suggested before, put a stock hammer spring back in it, I bet it works....

[Zuki Tyler]

What kind of ammunition are you using?

[77bawls]

Originally Posted by Zuki Tyler

What kind of ammunition are you using?

So far it's been nothing but PMC. I did just buy 420 rounds of 855.

[braxton357]

I bet you cut a leg off of the hammer spring didn't you. Replace it with another or buy a two stage trigger.

[77bawls]

Originally Posted by braxton357

I bet you cut a leg off of the hammer spring didn't you. Replace it with another or buy a two stage trigger.

I said I did the 15 minute trigger job.

I replaced the spring and cleaned everything. When I was looking at it in order for it to not be in battery the carrier needs to be about a quarter inch back which definitely wasn't the case. I put the new spring in there and if it fixes it, I'm going to have to get a Geissele, because I can't stand the stock trigger pull.

[Doc Holiday13]

Pop the rear takedown pin.
Pull charge back halfway so you can see the empty chamber.
Insert live round
Let the bolt down via charge handle.
Push the bolt into battery. It should settle in with a click and the bolt should cam fully.
Close the rifle up and push takedown pin in so the upper and lower are together securely.
Aim down range, turn safety off, pull trigger.

If it goes bang, then your hammer spring is fine. If not then there is a good chance you have a weak buffer spring and its not going fully into battery.

[kwrangln]

I'm betting hammer spring since you modded it. If the new hammer spring solves the problem then you are good to go. If you like where the hammer was at except for the reliability, then once you have the problem figured out you can get a set of JP yellow springs and lighten your hammer to do away with light strikes.

I'm not a fan of modding springs.

As for why some and not others? Could be as simple as a lube issue or variance between primers, who knows.

[ShmUDE]

i have the same issue in one of my AR's after doing the 15min trigger job. Figured i cut too much off the spring. Been waiting to get a new one or a 2 stage trigger to fix my issue.

you could hack the back half of the hammer off to lighten it. That would fix your issue too.

[Aggro]

Firing pin slides freely in bolt?

[64dumptruck]

Originally Posted by Aggro

Firing pin slides freely in bolt?

You should be able to shake the bcg in you hand and here the pin moving freely.

(jacking off motion)

[77bawls]

Originally Posted by Doc Holiday13

If it goes bang, then your hammer spring is fine. If not then there is a good chance you have a weak buffer spring and its not going fully into battery.

I'll try that

Originally Posted by ShmUDE

i have the same issue in one of my AR's after doing the 15min trigger job. Figured i cut too much off the spring. Been waiting to get a new one or a 2 stage trigger to fix my issue.

Good to know I'm not the only one.

Originally Posted by Aggro

Firing pin slides freely in bolt?

Yes.

[Ben Segrest]

Originally Posted by Doc Holiday13

Pop the rear takedown pin.
Pull charge back halfway so you can see the empty chamber.
Insert live round
Let the bolt down via charge handle.
Push the bolt into battery. It should settle in with a click and the bolt should cam fully.
Close the rifle up and push takedown pin in so the upper and lower are together securely.
Aim down range, turn safety off, pull trigger.

If it goes bang, then your hammer spring is fine. If not then there is a good chance you have a weak buffer spring and its not going fully into battery.

The buffer spring can't be the culprit if he manually closes the bolt and the rifle still doesn't fire.

[Hooligan]

Thread hijack- 77- if you want to try a factory trigger with the JP springs or a Gieselle- let me know and you can fondle mine. I tell ya- the JP springs have done wonders for the feel of the stock trigger. I know I measured the trigger pull but probably don't have the figures written down.

[77bawls]

Originally Posted by Hooligan

Thread hijack- 77- if you want to try a factory trigger with the JP springs or a Gieselle- let me know and you can fondle mine. I tell ya- the JP springs have done wonders for the feel of the stock trigger. I know I measured the trigger pull but probably don't have the figures written down.

Sure, we'll have to go shooting sometime.

[JonsYJjeep]

I just did the 15 minute trigger job on my MP15-22. Took it out out to the range. Never had a misfire before but this time I had about 12 out of 100 that misfired. Examined the 22lr and the rims had a soft impact from the firing pin. I noticed when firing that if I didn't release the trigger after pulling it I would get a misfire.

I considered adjusting the creep but I think I might lighten the hammer. But I'm not sure if this will fix it or not.

Glad I found this thread.

[Ben Segrest]

Originally Posted by JonsYJjeep

I just did the 15 minute trigger job on my MP15-22. Took it out out to the range. Never had a misfire before but this time I had about 12 out of 100 that misfired. Examined the 22lr and the rims had a soft impact from the firing pin. I noticed when firing that if I didn't release the trigger after pulling it I would get a misfire.

I considered adjusting the creep but I think I might lighten the hammer. But I'm not sure if this will fix it or not.

Glad I found this thread.

Did you cut/bend springs, specifically the hammer spring? If so, you'll need to lighten the hammer.