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mwt1980
04-25-2010, 9:53 PM
Okay here's the deal....

I am having a frustrating time with my AR at the moment. About 1 or 2 rounds a mag i have a dry fire. I eject the cartridge and it looks like the firing pin did strike the primer, however it is a light strike causing the round to not fire. You can see the difference between the spent cartridges and the dry fires. What the hell is going on?

It's not the ammo because it will do it with all ammo except 1. Have tried about 5 different ones.

Is it the bolt not closing all the way?

It is a basic trigger...would an upgraded one fix the problem?

It's not the upper because this is the second upper it has done this with...1st a Stag and now this YHM.

Im leaning towards it being a trigger/lower issue since that piece is the only constant.

What do you guys think?

pacrimguru
04-25-2010, 10:46 PM
first of all you are experiencing a misfire, not dry fire. dry firing is firing without a live cartridge chambered at all.

are you sure your hammer spring is installed correctly? what kind of buffer and buffer spring do you have? have you inspected your BCG to make sure the firing pin moves freely?

pyro3k2
04-25-2010, 10:50 PM
sounds like the problem maybe with your hammer spring not hitting hard enough, may want to try a new one just to see if it's the problem assuming everything is installed correctly.

telcolineman
04-25-2010, 10:53 PM
does it have a trigger job done? or lightened springs. these will cause light strikes and will not fire with cheap ammo such as wolf brown bear and others, Which ammo does not cause this problem?

mwt1980
04-25-2010, 10:55 PM
does it have a trigger job done? or lightened springs. these will cause light strikes and will not fire with cheap ammo such as wolf brown bear and others, Which ammo does not cause this problem?

American Eagle....stuff in the red box.

pacrimguru
04-25-2010, 11:06 PM
it's easy to get the hammer spring installed incorrectly. while installed incorrectly, it will seem to function correctly but will not strike as hard as it should. i suggest taking it out and checking it out.

ar15barrels
04-26-2010, 12:05 AM
Is it the bolt not closing all the way?

If it's the bolt not closing all the way, when the hammer falls, it finishes moving the bolt carrier forward, wasting most of it's energy.
Hence the light strike.

Cause can be anything from lack of lubrication to tight headspace caused by faulty parts or ammo to an under-gassed or over-weighted buffer that does not let the carrier properly rebound off the end of the buffer tube.

I'd bet on a backwards hammer spring though.

Army
04-26-2010, 7:27 AM
A little dent on the primer of chambered, but unfired rounds is normal. The firing pin is simply bouncing off the primer when the bolt stops. This is no concern what-so-ever.

If you are actually firing 2-3 rounds, and the next does not despite hammer fall, like ar15Barrels said...check your hammer springs.

It has two legs, both must be visibly on TOP of the trigger pin. This does two things; creates enough stored energy/hammer speed for proper ignition, and locks the trigger pin in place.

Also, make sure your gas key is screwed down tightly.

Not common, but look beneath the hammer and trigger assemblies inside the receiver for a loose primer that has fallen out of a case. This will either lock up the works, or prevent the fire control from operating correctly.

mwt1980
04-26-2010, 9:55 AM
How do i tell if the hammer spring is installed incorrectly? Is it an easy fix or should i take it to someone who knows what they are doing?

djleisure
04-26-2010, 11:10 AM
It's really easy. Just separate your upper from your lower and look down. In the picture below you can see the red part - it is the hammer spring. Make sure both of its "legs" are on top of the trigger pin (like the one you can see in the pic.)

http://www.gundigest.com/upload/images/2009%20Images/AR15-Trigger-2.jpg

GM_77
04-26-2010, 11:14 AM
^^ Nice pic!

ar15barrels
04-26-2010, 11:37 AM
http://i197.photobucket.com/albums/aa166/redtazdog/AR-15-Fire-Control-Group.gif

mwt1980
04-26-2010, 2:57 PM
Yep... Hammer Spring in backwards... Thanks for the help guys!