Interesting day at the range.  First, I hate the M1A.  it is simply not a good rifle for scoping.  No cheekweld possible with the scope so high (can't mount it much lower).

Then pull out an AR and get a full auto burst.  What the heck??  It did it twice in about 200 rounds fired.

Baffled by this one.,

Whatever.  A bad day at the rnage is better than, just about anything else.

James

You could be over at ASA talking to Bob. [:)]

LOLs.  Not much worse than that.

Actually, the full auto bursts were cool.  I just wish I had a swditch to control it (but that would be illegal without Class III).

And the overall day at the range was good.  The spacegun AR was flawless, and the carbine with ACOG was fun with and without the "bursts".

It only happened twice, but, I don't like having it happen without permission.  So if anyone knows the possible cause - let me know.  I do want to rectify this.

James

Jimmy,

What ammo were you using?

The only time this happened to me, was when I used PMP ammo (the one with the gazelle on the box).  Apparently, these are some very soft primers, and the force of the firing pin touching the primer while the bolt locked, set off the round.  Also, try a function check with your rile, and make sure that your disconnector works properly.

a slam fire... the SKS is notorous in the media cause ONCE a slam fire resulted in a death. when the bolt was thrown shut, the firing pin was stuck out and all ten rounds left teh barrel, one hit him in the head. i would definatly take a look at the gun, maybe have a gunsmith take a look.

Did you buy the rifle new? If not, it may be worn out or defective parts in the lower. A guy at my range had the same thing happen, except evertime he'd pull the trigger, it would fire the whole mag! Even if he took his finger off the trigger, it kept firing. Kinda dangerous, but fun for a few minutes. He ended up buying a complete lower parts kit from Bushy and all was well after that.

I had something like this happen to me when I changed from 20" to 16".  Seems that the action works faster and more violently, causing the disconnector to sometimes jump off the hammer when the bolt slams shut.  Try this: Take out the dsconnector - you'll see that there is a point at the front.  Lightly stone down the UNDERSIDE of this point (the surface that bears against the top of the trigger) to increase the disconnector engagement.  This is what worked for me, I've never had another problem with double-firing.

try replaceing the fire control parts one at a time, it is usually due to wear on these parts and may be dangerouse.

I love this board.  Answers 24 hours a day.

OK, I probably should have provided more info.  The rifle is a "frankengun".  The parts are:

Upper - FN reciever (new) with Wilson 16" barrel and freefloat handguards from my old ASA rifle.  Bolt carrier group from my old ASA rifle.  Total rounds through the old ASA about 200 (tough to shoot much with a single shot AR!)

The lower is more probably the culprit.  It is a brand new Bushy lower with brand new bushy parts that I assembled.  I have a RRA NM trigger in it.  My money is on the trigger.

When it went into burst mode it actually wasn't firing with the trigger all the way back or forward.  I use the fire, let trigger out to reset and fire again shooting mode.  It was at the reset point and fired/reset/fired/reset/fired in rapid succession.  I could feel the trigger pulse between the two points as if I had the fastest trigger finger in the world.

I plan on calling RRA to see what their opinion is.  I do like the trigger (in fact, I like the rifle quite a bit).

Oh, the ammo used was a variety:

Federal Eagle 55 grain (this stuff burst mode)
Federal Match (no bursts)
Winchester Q3131A (no bursts)

Jersey Gunny - I will check the parts you mention although with a NM trigger I'm not sure they are the same.

Mattsd - assuming you keep the thing pointed downrange, hard to get shot in the head.  I don't understand your story.

Thanks all.

James