An interesting (as in PIA) rifle problem

[Rivr_runnr]

At the O3GC this past weekend I had my rifle double once on stage 9 and on stage 1 on the hoser stuff it ran through about 5 ...should have seen the RO's eyes; he thougt I was fast! (at this point I am thinking high primers?) On that same stage, I had one load in to the chamber and not shoot. ejected it. Second shell, the same thing, then everything back to normal. A squad member picked up the live rounds and they did not have a primer punch at all. Not a mark on them. (at this point I am thinking gun problem?) On stage 6 the next day after the gun had been cleaned, shot more and performed flawlessly, it went into "do not fire mode"; three failure to fire on the RV stage in a row and then back to normal. No primer marks at all.

Anybody guess what is going on? I really need a direction.

I checked the specs on the bullets, they were all within spec.

[2011BLDR]

On the doubling is it a stock trigger? Or if not what aftermarket trigger? A worn out disconnect can cause doubling in both stock and aftermarket triggers. Additionally the pre travel and over travel screws in some aftermarket triggers can shift position and cause issues.

Out.

2011BLDR

[RiggerJJ]

Its not uncommon to see an AR that is set up correctly to double when shooting hoser stages/targets/rapid doubles. Could be bump firing or just riding the edge of the disconnect.

Did it double when shooting longer ranges? (IE, when you were operating the trigger slower?) if not I wouldn't worry about it.

for the failure to fires, I would look at making sure it is going into battery, check the lugs, dirty carrier?, etc (after checking ammo measurements...)

JMHO...

jj

[TRUBL]

I may have answer for the "Does Not Fire" mode

Are you guilty of not taking your bolt apart to clean? for maybe a couple thousand rounds? i was (raising my hand with a sheepish but nervous grin on my face)

Earlier this year....my rifle stopped functioning at Mesa. Further more.....when I dropped the hammer on an empty chamber...it sounded funny. Also....no dents on the primer, which is weird as you get dents on the primer just by dropping the bolt on a bolt. My problem was that the bolt/firing pin was so filthy dirty that there was a ring of crud between the head of the firing pin and the tail of the bolt. I cleaned it, has run ever since. maybe I'll do a little more preventative cleaning in the future.

The other thing it could be is....a broken firing pin. I've heard it can happen, never seen one break, but I've heard it happen. So if your firing pin is broke.....send me a picture of it.

Tim

[Rivr_runnr]

On the doubling is it a stock trigger? Or if not what aftermarket trigger? A worn out disconnect can cause doubling in both stock and aftermarket triggers. Additionally the pre travel and over travel screws in some aftermarket triggers can shift position and cause issues.

Out.

2011BLDR

JP trigger. I will examine the disconnect...Thanks

[Rivr_runnr]

Its not uncommon to see an AR that is set up correctly to double when shooting hoser stages/targets/rapid doubles. Could be bump firing or just riding the edge of the disconnect.

Did it double when shooting longer ranges? (IE, when you were operating the trigger slower?) if not I wouldn't worry about it.

for the failure to fires, I would look at making sure it is going into battery, check the lugs, dirty carrier?, etc (after checking ammo measurements...)

JMHO...

jj

Doubling did not happen on the LR stages. Great point. It is possible I was bumping it.

The loads/gun was going into battery. I will pull the entire assembly apart and double check the lugs. The carrier was clean

[Rivr_runnr]

I may have answer for the "Does Not Fire" mode

Are you guilty of not taking your bolt apart to clean? for maybe a couple thousand rounds? i was (raising my hand with a sheepish but nervous grin on my face)

Earlier this year....my rifle stopped functioning at Mesa. Further more.....when I dropped the hammer on an empty chamber...it sounded funny. Also....no dents on the primer, which is weird as you get dents on the primer just by dropping the bolt on a bolt. My problem was that the bolt/firing pin was so filthy dirty that there was a ring of crud between the head of the firing pin and the tail of the bolt. I cleaned it, has run ever since. maybe I'll do a little more preventative cleaning in the future.

The other thing it could be is....a broken firing pin. I've heard it can happen, never seen one break, but I've heard it happen. So if your firing pin is broke.....send me a picture of it.

Tim

Tim, this is a really good tip. I will examine the firing pin and the rear of the bolt where the firing pin rests or hits. I am not a clean freak, but do take the BCG apart after every session clean and lube it. I don't take it apart past that. Could be the bolt assembly itself. Thanks for your thoughts.

[mpeltier]

It does sound like your firing pin is sticking. Clean the bolt and firing pin of all carbon, and lube it really wet. Also clean the trigger real well.

[jmurch]

I agree (almost) with the above. Clean the bolt really well (carb cleaner) but dont lube the firing pin or the firing pin channel. There is no reason (IMO) to have any oil thre to collect dust, etc.

I fully dissasemble and clean the bolt every time. Not the barrel, sometimes the chamber, but always the bolt,

Jeff

Edited October 1, 2010 by jmurch

[Sako92S]

Check if the the hammer drops when you reset the trigger very very slowly. I had too short disconnector on my JP trigger group setup.