AR light primer strikes?

**steviesterno** · March 6th, 2010, 08:06 PM

Hey all,

I have a great spike's 20 inch AR build, but today i was getting light primer strikes. It seemed to hit the primers enough to leave a decent dent, but not enough to reliably set them off. I have no idea if it's the ammo or not (the ammo has been stored in a non-climate controlled building this winter).

all the 9mm and 45 stuff seemed to be fine though, just this damn 223. i could hit the round 3-4 times and most would go off, but not reliably. what can i do to increase the hammer speed/power and make sure she goes bang every time?

Steviesterno

**tdyoung58** · March 6th, 2010, 08:37 PM

What are you feeding it ?

**Legion_Prime** · March 6th, 2010, 09:07 PM

First off, open up the rifle and check the hammer spring. It is quite easily installed incorrectly and will give the same symptoms you described. It's hard to describe exactly what it looks like but a google image search should bring up plenty of pictures of the triggergroup.
Excluding faulty ammo though check to make sure that the shoulder of the firing pin is clean and free from carbon buildup, same goes for the FP channel in the bolt. Make sure there is nothing caught behind the bolt face as this can prevent the FP from protruding fully. Also scrub them well with a solvent to ensure there isn't any gummy buildup or residue which can cause the FP to stick and impede it's action. Remember the FP only gets a very light coat of lube. Also be sure to check the tip of the firing pin to see if it is cracked, blunted or mushroomed, if so replace it.
Have you chambered any of those rounds previously? Because the FP hitting the primer during chambering can desensitize the primer after a couple rechamberings. Try running a couple mags of new 5.56 milspec factory ammo with hard primers, if you still have problems try again with .223 SAMMI spec factory ammunition. If either has any of the same issues the problem is likely in the rifle.
If you check all this and are still having issues I would recommend a new hammer spring.

**steviesterno** · March 7th, 2010, 09:45 AM

i was feeding it good production ammo (pmc, i think) but it hasn;'t been stored well. I am also thinking now that I do have the trigger spring in backwards. I always seem to mess up something during a build and have to tear down and fix it. I'm going to try that fix first, and run some newer production ammo through it. I checked the bolt carrier group and firing pin, and they were fine. oh well, it will give me something to tinker with.

now is there an easy way to flip the trigger spring?

steve

**Legion_Prime** · March 7th, 2010, 07:03 PM

Yeah, I tried to order them by most common cause and easiest to check first. Flipping the hammer spring is pretty easy, just open it up and drop the hammer. Then you push out the hammer pin and the hammer should pretty much push itself out of the lower. Then just turn the spring around and stick the hammer back in. Let us know how it works out.