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bullittsam159 04-04-2012 07:37 PM

Ar-15 dented primers but not firing.
This only happens when bump firing. The primers are dented but do not detonate and it happens about 4 times per mag. Anybody had the same problem? Are there any upgrades I can do to fix it so it will bump fire more reliably?

purehavoc 04-04-2012 07:57 PM

heavier hammer spring possibly , try different ammo and see if it does the same thing . timing may be off a bit, bolt not closed all the way when the hammer hits causing it to ride the carrier and causing a light strike . Head space issue but I doubt that one . .
Got a pic of the light struck primer ?

Second option
Dont bump fire it :D

ryguy00 04-04-2012 07:59 PM

Are you absolutely sure its not the ammo? Usually when a primer is dented, the round will fire. Unless youre talking about a light primer strike which ive never encountered in my ar. I would try a different brand of ammo first before buying any parts.

I know its not the same as your problem but i cannot run tula ammo in mine. It does not have enough power to cycle the bolt and leave the empty inside the chamber. All ammunition is not created equal.

robocop10mm 04-04-2012 08:08 PM

Post a pic of the "dent". It sounds like it may be the typical small mark made by the non-spring loaded firing pin. If you are bump firing you may be releasing the hammer before the bolt is locked. The AR is made to not fire out of battery so the hammer is not even hitting the firing pin.

bullittsam159 04-05-2012 02:22 PM

Don't have any pics of the dented primers I'll take a pic when I shoot this weekend of I can get out. It happened with Remington .223 and federal 5.56 so I really hope its not the ammo lol. The primers have serious dents in them not small marks. They look about the same as the fired rounds, I was think maybe the hammer is following the bolt back until it's closed and hitting the primer but without enough speed to detonate but enough power to dent? Does this sound possible? Also probably not headspace as it only happens bump firing and the gun has more than a few thousand rounds through it.

bullittsam159 04-05-2012 02:23 PM

Robo cop that sounds like it could be right. The primer dent looks to be as deep as the successful rounds though so idk. I know I'm not the only one bump firing so there must be a way to fix this.

primer1 04-05-2012 03:01 PM

I find a dented primer anytime I cycle a round (dpms) then eject it without firing. Being the nervous type, I showed it to the dealer and they said the same about the floating firing pin. Still makes me a little nervous.

homelessguy01 04-05-2012 03:25 PM

I've heard of a guy using large pistol primers by accident when reloading and ended up dumping a mag. I think alot of semi centrefires can slighty dent the primer when the bolt slams home. So this guy having loaded pistol instead of rifle primers got quite a fright!

FCross7 04-05-2012 03:36 PM

Here's an easy way to fix it:

Stop bump firing. :D


locutus 04-05-2012 03:38 PM

First, why on earth would you "bump fire???"
If the weapon fires normally in normal firing, you don't have a problem.;)

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