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7/5/2004 6:45:39 PM EDT
I put about 300rnds through my AR over the weekend and during this period I experienced a slamfire.  I was about 1/2 way through a mag and after firing one shot the bolt returned home and the gun fired again.  Is this common?  Does it have alot to do with the ammo used?  Is there any way to prevent it?  Thanks.
7/5/2004 7:25:45 PM EDT
[#1]

Quoted:
I put about 300rnds through my AR over the weekend and during this period I experienced a slamfire.  I was about 1/2 way through a mag and after firing one shot the bolt returned home and the gun fired again.  Is this common?  Does it have alot to do with the ammo used?  Is there any way to prevent it?  Thanks.



Raised primer is the only thing I could think of - what kind of ammo were you using?
7/5/2004 7:40:48 PM EDT
[#2]
Winchester white box 55gr. FMJ.  It came in a box of 40rnds.  Lot # VB71.  Does this happen often?
7/5/2004 7:48:55 PM EDT
[#3]
Do AR type rifles still do cook offs? Or is this past history? Fire retartdant britches on, flame away!

Mike
7/5/2004 7:53:42 PM EDT
[#4]
What kind of trigger do you have installed?? I know some say that they are not recommended for some types of ammo.
7/5/2004 7:53:51 PM EDT
[#5]
Check for lumps of any sort of contamination on the bolt face.

Make sure the firing pin hole in the bolt is clean, free of defects, and the firing pin
itself is also clean and free of defects.   LIGHTLY lubricate the firing pin.

There's really not much else that can cause a slamfire unless you had a round
with a primer that was so sensitive that just chambering the round set it off
with that TINY, LIGHT little primer strike the firing pin gives to every round
as the bolt slams shut.

Did you save the case, by chance?    It would give you a clue.  Whatever set off
the primer DID make a mark and shows you where to look.

CJ
7/5/2004 7:57:30 PM EDT
[#6]
The trigger is factory Colt.  I do have the case and it has a very light firing pin indent.  It is so light that it shouldn't have gone off.  The barrel was pretty hot at the time but I'd imagine that didn't make a difference.
7/6/2004 4:13:19 AM EDT
[#7]
Then you probably just had an oversensitive primer with a thin wall,  I'd wager.  Nothing to worry about unless it happens again.  And then I'd switch to different ammo.

CJ
7/6/2004 4:00:51 PM EDT
[#8]
Will do...thanks everyone.
7/6/2004 4:48:57 PM EDT
[#9]

Quoted:
Winchester white box 55gr. FMJ.  It came in a box of 40rnds.  Lot # VB71.  Does this happen often?



From what I have heard the Winchester White Box ammo have very soft primers.  
7/6/2004 4:56:20 PM EDT
[#10]
That could explain it then.  I'll try some other ammo and if it happens again I'll be back here posting again.  Thanks.
7/7/2004 4:45:19 AM EDT
[#11]
In '00 a Wisconsin National Guardsman was killed by a slamfire during a live fire training exercise. In basic, every recruit gets a lecture on "slamfires, hangfires, and misfires (including cook-offs) and the bottom line here is though they are rare, never "cock and lock" unless your muzzle is to the ground or in the air, and just as important, always try and be aware of what direction your fellow team members have their muzzles pointed. Now this would seem a very basic safety precaution, except, the aforementioned Guardsmen weren't following that rule with tragic results...safety contiousness has to be engrained in the brain of every shooter at all times. These firearms are a great source of fun and recreation, but the responsability involved is very deep. Any slam fire that causes no damage is a warning, and a reminder.
7/7/2004 9:04:51 AM EDT
[#12]
While on the subject of accidental ignition, has anyone with fumble fingers set off a round by dropping it on the ground?
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