AR15 not firing

[PolishMike]

Yes I did, but I assumed that was not the problem because the rifle did fire two rounds in the first mag.

Than when I tried to fire the second mag with the next two rounds, it did not fire again. Even once I switched out the mags tried it maybe 10 times never fired.

Also I did not think the hammer spring was the problem because the hammer still drops when I dry fire.

If the hammer spring is in backwards the hammer will act like normal. It will also cause weird FTF issues because sometimes it will hit with enough force to set off a primer and other times it won't. It will cause the exact issue you are describing and is the most likely cause.

Take the upper off and post a pic of the trigger group.

[Jason Singh]

Could be lots of things. Try cleaning really well and lubing everything. ARs like it wet. Check hammer spring direction. Try real ammo. Try a different BCG.

Is it ejecting normally? Are you hand cycling it after it doesn't fire?

I did clean it last night, it was VERY dirty, Mostly everything was black inside. I cleaned the BCG, opened all the little pins and parts cleaned and lubed them. I cleaned the hammer and springs.

the rifle did fire two times before failing. So I assumed the hammer is in correctly. It does dry fire.

It did eject normally, and I did not have to hand cycle at all, the rounds chamber every time normally, just wont fire.

If it fails again, I will try a different bcg, I dont have any others So i will talk to the range and try to use one of theirs, and maybe go from their. If it works, Ill end up buying a new BCG.
The one I currently use is shadow ops weaponry nickel boron bcg which we all know has closed down.

[Jason Singh]

If the hammer spring is in backwards the hammer will act like normal. It will also cause weird FTF issues because sometimes it will hit with enough force to set off a primer and other times it won't. It will cause the exact issue you are describing and is the most likely cause.

Take the upper off and post a pic of the trigger group.

give me five minutes and I will post it.

[Jason Singh]

Heres some

[Jason Singh]

I hope these 4 will do

[Jason Singh]

If the hammer spring is in backwards the hammer will act like normal. It will also cause weird FTF issues because sometimes it will hit with enough force to set off a primer and other times it won't. It will cause the exact issue you are describing and is the most likely cause.

Take the upper off and post a pic of the trigger group.

It is okay, I just googled it and checked it, the hammer spring is in correctly.

[PolishMike]

Looks correct

[ARDude]

I say try different ammo.

[ScottsBad]

No - Its not. It cannot be "mil spec" and have "a bunch of custom parts". Your semi auto AR15 is NOT mil spec.

AR-15s do not use clips. They use magazines. The term is NOT interchangeable and means two very different things.

Failure to fire causes include:
Too much lube/dirt on firing pin
Incorrect installation of hammer spring
Bad ammo
Missing/broken firing pin

1) Make sure the bolt is going into full battery
2) Make sure the hammer spring is correctly installed
3) Report back

^This is a good start, but I would add:

Pull the firing pin and check to see if broken or bent. Clean the BCG, and reassemble it PROPERLY. Ensure the firing pin extends from the face of the bolt when the firing pin is pushed forward inside the assembled BCG in compressed in-battery position.

Buy a box of regular ammo.

At the range, load one live round, release the bolt carrier so that it slams into battery. In other words, don't ride the charging handle or otherwise impede the Bolt Carrier Group (BCG) as it pushes the round into battery. Look into the dust cover and ensure the BCG is all the way forward. Push the forward assist button hard a couple of times to ensure that the bolt is in battery.

OK, now shoot. If it shoots, load a frangible round or two the same way you did above.

If it doesn't fire check the primer of the cartridge you just tried to shoot. Is there a dent in the primer, I mean a good deep dent. IF you don't know what a good primer strike should look like pick up some brass from other shooters at the range and inspect the brass.

If it is a light dent, then it is likely a weak or improperly installed hammer spring. I would also buy a new firing pin (like $8) and install it just for grins. Then you'll have a spare if it's not the firing pin.

[ScottsBad]

It is okay, I just googled it and checked it, the hammer spring is in correctly.

Pictures look correct...who did the hokie rattle can paint job? Sorry, I couldn't help myself.

Looks almost like there are metal shavings on top of the hammer spring. I would douche out the lower and re-lube. If it were me.

Concentrate on the Bolt Carrier Group. I think that's where the problem is...That or bad ammo.

[Jason Singh]

Update for you guys.

I cleaned the rifle, it was very dirty.
I used frangible rounds from team never quits, and it fired without any misfires at all. Shot 100 rounds.

thanks for the help you guys!!

[Lonestargrizzly]

You need to be using 4 parts gasoline and 2 parts oil for a milspec AR15. The gas system will run really dirty if you just use straight gasoline. And also before you shoot it, you need to pump the forward assist 8 times in order to prime the gas uptake system.
If that doesnt work try pulling the charging handle until it starts up. Then try with the sling swivel in the forward position, then the rear position.

[MattH2h]

You need to be using 4 parts gasoline and 2 parts oil for a milspec AR15. The gas system will run really dirty if you just use straight gasoline. And also before you shoot it, you need to pump the forward assist 8 times in order to prime the gas uptake system.
If that doesnt work try pulling the charging handle until it starts up. Then try with the sling swivel in the forward position, then the rear position.