AR-10 Jam. Any ideas?

[ndh87]

Went shooting yesterday with my friend. He has an AR-10 that kept jamming. I stopped and watched while he shot it. I noticed that the extractor would pull the empty shell out of the chamber and all the way to the rear. Then move foward and pick up the next round without kicking out the old shell.

Anyone have any ideas whats going on here? My best guess was that his ejector isn't working. When we loaded a single round and fired the rifle the empty round would get pulled out of the chamber, the bolt would move its full length without ejecting the spent casing. Then the empty would get mashed back into the chamber.

However, when i chambered a round then pulled the charging handle again the round would eject properly.

Anyone know what is causing this or who to fix it?

 

[H2O MAN]

 

[rcmodel]

The only thing it can be is the ejector spring & plunger are stuck inside the bolt.

You need to dissemble the bolt completely and clean all the gunk out of it.

rcmodel

 

[ndh87]

The gun is almost brand new and only has about 100 rounds through it. And this problem has been going since the first mag.

 

[Wes Janson]

So it had gunk in it from the factory. Perhaps it wasn't test fired, or perhaps some debris got caught up in there. Regardless, rcmodel's solution will fix the problem.

 

[TIMC]

I have seen this happen with an AR-10 before. The gas block had moved a little and was not lined up correctly with the port in the barrel. That would be the first thing I'd check.

 

[Wes Janson]

I have seen this happen with an AR-10 before. The gas block had moved a little and was not lined up correctly with the port in the barrel. That would be the first thing I'd check.

If the gas port was blocked, the rifle would not cycle at all, period. Assuming that the description is correct and the bolt is making it fully to the rear of the action, then pretty much the only possibility left is some sort of ejector/ejector spring failure.

 

[TIMC]

I didn't say blocked. If the gas block moves and partially closes off the port it will create the problem stated above. I was not talking from hear say, I know this first hand.

This happened on a friends Bushmaster AR-10 about 6 months ago we went over everything before we found the cause. The bolt will look like it is going back all the way but it was not quite making it.

 

[rcmodel]

If the front of the empty case is clearing the front edge of the ejection port, it should kick the empty out.

If it isn't, it would get caught on the barrel extension when it tried to go back closed.

rcmodel