Lower Goes Full Auto

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[ARCHIVED THREAD] - Lower Goes Full Auto

Posted: 12/15/2002 10:10:47 AM EDT

Recently purchased a DPMS pre-ban lower. Can't tell you much more about it or the fire controls used. Shot it for first time today mounted to a DPMS, pre-ban CAR, 16",flat top upper. When the trigger is pulled, held back, then slowly released it fires another round on release. If the trigger is not completely released then the gun goes full auto.

We tried it with three other uppers, a Bushmaster, a M&A and a Colt. It did the same with all of them. I should also mention that it will do this dry firing. If I dry fire the gun and hold the trigger back and pull the charging handle back and release it the trigger will also release, eg it dry fires again.

Help, advise, ideas appreciated.

Did a search but could not find much.

Posted: 12/15/2002 10:26:41 AM EDT

[#1]

If it's got standard fire controls, just change them out with new. The disconnector and or spring are probably worn.
Hard to help if you don't know what you have.

Posted: 12/15/2002 11:13:27 AM EDT

[#2]

Gecko, you have two choices.

1. Replace the entire FCG. The disconnector is not your only problem.

2. Refit the FCG. The hammer sear has either worn, or been milled to remove creep. This will cause the disconnector to release the hammer before the trigger sear(edge) is under the hammer to allow the trigger to retain the hammer, instead of slipping/deflecting past. Adjusting the disconnector may be the only thing needed, but other parts may need to be adjusted too.

And, before I get scowled by Royce, How are your smith'g skills, Adjusting the FCG is not for the novice. If FCG tunings is beyond you, just replace the FCG. If not, I can walk you threw the adjustments and refinements.

Posted: 12/15/2002 11:27:11 AM EDT

[#3]

i have an AK that does this. i can empty a mag. at full auto if i hold the trigger right. lots of fun.

my only question is "WWBATFD" (what would BATF do?)

Posted: 12/15/2002 11:37:23 AM EDT

[#4]

The BATF shop boys can get a bucket of molten aluminum running full auto in a couple hours. What do you THINK they'd do with a gun that did what you describe?

Posted: 12/15/2002 11:41:26 AM EDT

[#5]

Why are you complaining? Instead of paying $6000 or more for Class III M16/M4, all the waiting, all the background check, and all the paperwork, you got yourself a full auto! I'm only kidding.

Posted: 12/15/2002 12:03:17 PM EDT

[#6]

Quoted:
The BATF shop boys can get a bucket of molten aluminum running full auto in a couple hours. What do you THINK they'd do with a gun that did what you describe?

View Quote

ROTFLMAO!!!!!!!

You have to admit that the shop boys at the BATF could even get a single shot to run full auto in less than a couple of hours.

Never say it can't be done when it comes to proving their case in court!

Posted: 12/15/2002 12:21:47 PM EDT

[#7]

i have been meaning to get a new trigger group for that AK. i just havn't been needing to fire it (i have others). i guess since i just posted that fact i better pull the gun apart so when the BATF lurkers show up at my door the worn parts won't be in the gun. -destroyed.

GECKO, i suggest you do the same since it is now known by everyone that your gun fires in full, intentional or not.
Big Brother is watching this forum. [(:)]

Posted: 12/15/2002 2:26:41 PM EDT

[#8]

Yeah. It was kind of fun for a while, but need to fix it.

What parts constitute the Fire Control Group. Hammer, Disconnector, Trigger, springs ???

Gecko

Posted: 12/15/2002 6:16:44 PM EDT

[#9]

In regards to your FCG, just replace the trigger, hammer, and disconnector, and not the springs.

The trigger goes for $15, the hammer for $20, and the disconnector for $6. Or, you can just buy the blister pack with a new selector for $49.95.

[url]http://www.shooterstore.com/acb/showdetl.cfm?&DID=90&Product_ID=6538&CATID=494[/url]

Posted: 12/16/2002 8:28:44 AM EDT

[#10]

This is a bad thing??

Posted: 12/16/2002 2:50:47 PM EDT

[#11]

Quoted:
This is a bad thing??

View Quote

Not if you don't mind a nightly ass raping by your new cell mate Bubba!!!

Posted: 12/17/2002 1:56:27 AM EDT

[#12]

Thanks guys. New FCG in the mail. Should fix the problem. Now if I can find some pin punches, but looks like I have to order them from Brownells.

Need to correct this as I'm too old to learn how to sleep with my back to the wall.

Posted: 12/17/2002 4:47:34 PM EDT

[#13]

You don't need to use a punch set to replace the FCG, Even a small nail will work.

Start with the hammer pin and press it out. The hammer pin is only held in by a small spring in the hammer that rides in the center grove of the hammer pin. Once past the indent, the pin will push right out. The hammer spring holds the trigger pin in. So once you have removed the hammer, the trigger pin just pushes out.

Just to give you a idea, I have even pulled a FCG in the field by using nothing more than a ball point pen. Remember to hold the hammer in line with the holes when driving the pin out of the receiver to allow the pin to glide freely.

Hope this helps.

Posted: 12/17/2002 5:12:56 PM EDT

[#14]

A bullet from an unfired round makes a good punch as well, just be careful not to force it too hard. It should come out with just a little effort.

Posted: 12/19/2002 3:43:54 AM EDT

[#15]

The really bad thing about this malfunction is that it is neither controllable nor predictable.
On any given day, you may not be able to stop it, or it may fire without you pulling the trigger...just from a bump to the gun.
ecko, a setof steel pin punches is $14 @ Sears...$10 or the no-name brand.

Posted: 12/20/2002 1:42:14 AM EDT

[#16]

Royce:

It's exactly as you discribe! Unsafe as he**. Got the new FCG and will replace this weekend.

Posted: 12/20/2002 3:00:24 AM EDT

[#17]

You are experiencing "untimed automatic fire" likely caused by worn parts (concur on disconnector and maybe hammer/trigger interface. This is extremely unsafe, as it is causing the hammer to strike the firing pin and primer at the wrong cycle during the bolt carrier assembly's travel, and could cause your rifle to KB. Do not shoot it any more until you get those parts swapped out for new ones.

Posted: 12/24/2002 3:41:48 PM EDT

[#18]

tAKE SOME PICS OF WHAT YOUR OLD FCG LOOKS LIKE SO PEOPLE CAN LEARN WHAT TO WATCH WITH WEAR ON THEIR GUNS.

Posted: 12/25/2002 3:44:15 AM EDT

[#19]

Your disconector is dropping the hammer early in the trigger return stroke. You can increase engagement by shaving about .030" off the underside of the front foot of the disconector. This will allow it to rotate foward further and increase the engagement on the hammer. There is no need to change out all the rest of the parts.

Posted: 12/25/2002 3:53:05 AM EDT

[#20]

New FCG seems to have solved the problem. All function tests seem OK, however weather so bad can't get to the field to test fire.

Sorry, no digtial camera. Old parts have been destroyed by grinding up!

Posted: 12/25/2002 4:34:37 AM EDT

[#21]

Quoted:
tAKE SOME PICS OF WHAT YOUR OLD FCG LOOKS LIKE SO PEOPLE CAN LEARN WHAT TO WATCH WITH WEAR ON THEIR GUNS.

View Quote

[:k][:k][:k][:k][:k]

1 of 4 posts? Hello Mr. ATFMAN I am sorry but we dont help other people convert their rifles into illegal full auto.

Get Lost Troll

[ARCHIVED THREAD] - Lower Goes Full Auto

AR-15 » Troubleshooting

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