AR BCG troubles

Nottherealfranco · Dec 31, 2014

clandestine said:
When you removed the bolt head and inserted it into the upper it still sticks out right? If so the gas tube is bottoming out inside the gas key on the bolt carrier. If you look at my cut away bolt youll see that there has to be a space, if not it shuts the gas system off. Even if you got it to slam close it wouldn't cycle because it's blocking G off the relief port in the carrier that causes the bolt head to unlock under pressure. Someone put a mid gas or custom length gas tube in a carbine upper gas system, or the like.

Those bastards...

Guess i'll be calling JSE in the morning to get this all sorted out..

Hopefully they won't give me a ton of shit.. I purchased this over a month ago and have been slowly working on it.

Thanks everyone for their input.

Fox123 · Dec 31, 2014

I think he means if the gas tube was stopping the carrier from going any farther forward, then there would be a gap between the face of the bolt carrier and the rear of the barrel extension. In his case he is saying that the carrier, with bolt removed, is sitting flush with the barrel extention and there is still that amount extending out the rear of the receiver.

clandestine · Dec 31, 2014

I can tell by looking at the pic that the gas tube is sticking out too far. So it's either not roll pinned in place, or its the wrong length one, or worse off the front sight base barrel shoulder was cut back too far resulting in the gas tube setback.

Boom Boom · Dec 31, 2014

Nottherealfranco said:
I bought this as a 'blemished' item.. I don't know if i can return it...

It's not a blemish issue. The upper is badly Bubba'd and not usable as is.

clandestine · Dec 31, 2014

Nottherealfranco said:
Those bastards...

Guess i'll be calling JSE in the morning to get this all sorted out..

Hopefully they won't give me a ton of shit.. I purchased this over a month ago and have been slowly working on it.

Thanks everyone for their input.

Where are you located? Are you in the glen burnie area? If JSE does not help let me know and I'll help you out. I can do this stuff in my sleep, it can be fixed.

clandestine · Dec 31, 2014

Boom Boom said:
It's not a blemish issue. The upper is badly Bubba'd and not usable as is.

Agreed. That's a Bubba indeed.

clandestine · Dec 31, 2014

If you have the capability to remove the gas tube roll pin and the gas tube and the reinstall the bolt group, this will lock the problem down for certain.

Nottherealfranco · Dec 31, 2014

Fox123 said:
I think he means if the gas tube was stopping the carrier from going any farther forward, then there would be a gap between the face of the bolt carrier and the rear of the barrel extension. In his case he is saying that the carrier, with bolt removed, is sitting flush with the barrel extention and there is still that amount extending out the rear of the receiver.

Precisely. However I know very little besides the basics with AR's, hence me posing this question to you fine people of the internet.

clandestine said:
Where are you located? Are you in the glen burnie area? If JSE does not help let me know and I'll help you out. I can do this stuff in my sleep, it can be fixed.

I'm not in the Glen Burnie area, but i'm close enough id be willing to make the drive to get this sorted.

clandestine · Dec 31, 2014

Nottherealfranco said:
Precisely. However I know very little besides the basics with AR's, hence me posing this question to you fine people of the internet.

I'm not in the Glen Burnie area, but i'm close enough id be willing to make the drive to get this sorted.

Keep me updated and I'll help you out.

K.C.Dean · Dec 31, 2014

If you built this gun from scratch, are you sure you have the correct length gas tube? If your gas block can be removed then remove it and see if the BCG will fit. If it does fit then try to slide the gas tube back in and see how far it goes in. If it doesn't fit then the gas tube is probably tge wrong length.

Man I type so slow that by the time I wrote this, it had been explaned.

vinjet700 · Dec 31, 2014

looks like a lotta brass in the bolt chamber. After everything Chad said, lube is your friend....

Merlin593 · Dec 31, 2014

I guess it wasn't test fired before they shipped it to you?
Both of the complete uppers I've purchased were test fired prior to shipment
Good luck getting this resolved with the vendor

sailskidrive · Dec 31, 2014

Those feed ramps look like Century quality work to me...

Nottherealfranco · Dec 31, 2014

Small update:
Called JSE, and a nice woman named Chelsey (Chelsea?) answered the phone. Very polite, and while she was unable to help me, she's going to have the techs call me back later today to try to get this sorted out. I'll raise concerns about the quality of the feed ramps, as well as the length of the gas tube.

Merlin593 said:
I guess it wasn't test fired before they shipped it to you?
Both of the complete uppers I've purchased were test fired prior to shipment
Good luck getting this resolved with the vendor

My upper was test fired, and delivered with the BCG inside the upper. I'm sure the upper functions as-is, but how reliable or safe is my concern.

Update #2:

By some miracle i was able to get the gas tube out of the gun without completely ****ing it up. I put the bcg back in, and it's still sticking out. Took the bolt out of the carrier and inserted the carrier, and it's still sticking out. So the gas tube was not the problem..

Boom Boom · Dec 31, 2014

Does the forward assist work properly? Should be spring loaded. I received a new upper once upon a time where the assist spring was broken or missing. Took me a few minutes to realize the problem. The assist would slip down and snag the carrier, causing a similar problem to what you're seeing.

Weber · Dec 31, 2014

Pull the gas tube and see if the BCG goes in correctly.

Polish the feed ramps to be smooth.

Nottherealfranco · Dec 31, 2014

Boom Boom said:
Does the forward assist work properly? Should be spring loaded. I received a new upper once upon a time where the assist spring was broken or missing. Took me a few minutes to realize the problem. The assist would slip down and snag the carrier, causing a similar problem to what you're seeing.

With the bolt completely out, i'm able to depress it fully, and it returns to it's original position. With the bolt in, the assist contacts the bolt and does not fully depress.

clandestine · Dec 31, 2014

Nottherealfranco said:
With the bolt completely out, i'm able to depress it fully, and it returns to it's original position. With the bolt in, the assist contacts the bolt and does not fully depress.

That's normal.

As far as the feed ramps go, the barrel should be removed to do the ramps. Since the lower ramps are already ground they won't polish as the same rate and will undercut the upper ramps because they are softer.

clandestine · Dec 31, 2014

Nottherealfranco said:
Small update:
Called JSE, and a nice woman named Chelsey (Chelsea?) answered the phone. Very polite, and while she was unable to help me, she's going to have the techs call me back later today to try to get this sorted out. I'll raise concerns about the quality of the feed ramps, as well as the length of the gas tube.

My upper was test fired, and delivered with the BCG inside the upper. I'm sure the upper functions as-is, but how reliable or safe is my concern.

Update #2:

By some miracle i was able to get the gas tube out of the gun without completely ****ing it up. I put the bcg back in, and it's still sticking out. Took the bolt out of the carrier and inserted the carrier, and it's still sticking out. So the gas tube was not the problem..

Well, that's got me puzzled then too. I'm at a loss without having it in front of me to gauge. The carrier is my only guess without seeing it in person. Do you have a second carrier to test?

Nottherealfranco · Dec 31, 2014

clandestine said:
That's normal.

As far as the feed ramps go, the barrel should be removed to do the ramps. Since the lower ramps are already ground they won't polish as the same rate and will undercut the upper ramps because they are softer.

More work than I should probably have to do on a brand new upper. When JSE calls back i'll mention to them that the feed ramps are ground and not polished like they should be, and mention the debris that's all over the barrel extension.

clandestine said:
Well, that's got me puzzled then too. I'm at a loss without having it in front of me to gauge.

Since the gas tube isn't the issue, and the carrier doesn't fit with the bolt removed, I'm thinking it's something out of spec with the carrier. I don't know if they make different spec BCG's, but this one is not fitting properly.

clandestine said:
. Do you have a second carrier to test?

Unfortunately I do not. I decided against buying a second carrier because this upper already came with one, and I am trying to stay on a reasonable budget for my first build.

AR BCG troubles

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