View Full Version : AR 10 - New Build - Trouble with the BCG

August 23, 2010, 06:52 PM
I can remove the takedown pin and open up the weapon. Even in this position I cannot get the BCG to slide open. Pulling back on the charging handle gives about 1/4 inch movement.


I just finished my first AR 10 (I've successfully completed an AR 15). This is a Armalite upper, lower, and LPK.

When I rack the BCG it works fine. The safety works. The magazine locks in and releases properly.

With respect the trigger I didn't want to dry fire, so as a "test" I
Racked the BCG (it locked in place properly)

Dropped in a spent .308 Win cartridge (I put a tiny piece of blue tape
over the dented primer case)

Hit the Bolt Release button (and the BCG racked properly)

Pulled the trigger

Up to this point, everything went well. Or so I thought.

I cannot rack the BCG open.

What can be the difference: Without a cartridge it opened properly. With one in the chamber it doesn't ???

If you have any ideas, please pass them along !

Thank you.

August 23, 2010, 07:52 PM
i assume it was a spent casing from another rifle. The reason you have to re-size brass after it is spent is because it expands after it is fired. There is a possibility that the brass is wedged in the chamber.

August 23, 2010, 10:21 PM
Its time to perform the immediate action drill:
1. Drop the mag.
2. Collapse the stock to its shortest position.
3. Hold the rifle vertically with the butt about 6-8 inches above the carpeted floor.
4. Slam the butt against the carpet while simultaneously pulling down on the charging handle. The inertia of the BCG plus force on the CH should unlock the bolt and extract the empty case.
5. You might have to repeat #4 a couple times if the case is wedged tight.

Another method is to pad the blade of a big screwdriver with several wraps of tape. Then insert the screwdriver through the mag well and pry the bolt carrier to the rear. This is done by placing the screwdriver blade in the gap between the front of the bolt carrier and rear of the barrel extension, then twisting the screwdriver.

Next time, use a full length sized case.

August 23, 2010, 11:24 PM
To both of you, thank you for your help. I was able to pry the BCG back far enough to unlock it, and then I used one of my more sturdy cleaning rods and was able to tap out the jammed cartridge.

It appears that
(1) - I don't know anything about the physical properties of a spent shell, and

(2) - Maybe I should invest in snap caps for all of my firearms

As always, the TFLers have an answer !

take care,

August 24, 2010, 06:58 AM
You can also use a milsurp m16 cleaning rod, some times it gives it that little extra.:) Hey what about that tape??:confused: I wouldn't put tape on the bottom of around as that competes for head space withe the cartridge!!:eek: And IS likely the culprit, If it's a new rifle MAKE absolutely sure the chamber is spotless. I wouldn't think that an occasional dry-rire from this rifle would hurt anything!:)