10.3 DD with A5 system

[elpotro]

A double feed is two live rounds jammed in the action. It's caused by a bad magazine. Are you certain it's a double feed? Or, is the spent case and a live round caught in the action? If the latter, your extractor spring is bad.

Don't buy a new gas block. What will a new gas block do the old one doesn't? Does the gas block you have rattle on the barrel if the screws aren't snug? Is gas blowing out from between the block & barrel? Is gas blowing out around the gas tube? If not, the gas block is fine unless it's blocked inside.

Assuming you're using full power ammo, your AR is short stroking. It should lock back with an A5A2 and a green spring. The two most common causes of short stroking (aside from weak ammo) is a leaky gas key and a worn gas tubes. Gas tubes wear aft the place they fit into the gas key. The third cause of short stroking is bad gas rings.

Gas keys can leak even if the screws are tight. Try your AR with a BCG you know is good. Test it with the A5A2 & green spring installed. If your AR wil not function with an A5A2 buffer & green spring with good ammo, you've got a problem- and it's not the buffer or spring.

Do yourself a favor and replace the extractor spring before any further troubleshooting. It wil save you a lot of time, ammo & frustration. Install a Colt or Sprinco M4 spring. No O ring. This bears repeating- no O ring. Accept no substitutes.

Thank you very much! I will do all this. No O Rings. Replace the extractor. I will also replace the gas tube just in case. Everything is brand new... this is why I did not go to the technical side. But what you say makes perfect sense. The BCG is a brand new BCM and the gas tube is new. I will do all this and let you know. Unfortunately I have to wait until next weekend. Oh, by the way... I misspoke when I said double feed. It was exactly what you described a spent round and a live round in the action. The ammor I use is from freedom munitions 556, 62 gr. I am very grateful for your time and advice. Thank you!

[prepare]

So far all the components you have mentioned are quality brands. Where did you get the gas tube?

[elpotro]

So far all the components you have mentioned are quality brands. Where did you get the gas tube?

Ballistic Advantage. I am considering buying a DD BCG... I wrote to BCM to see if they would replace it (Don't have an answer yet). I do have 2 Ballistic Advantage spare BCG.

[jackblack73]

Have you done a lock back test? Load one round, fire with an empty mag, and see if the BCG locks back when fired.

I don't see why BCM would replace the BCG since you haven't even confirmed it is the issue. If you do everything Mistwolf says at once you won't identify the issue. I would start with replacing the extractor spring only. How old is the BCG? BCM had a run of bad extractor springs a couple years ago.

[RHINOWSO]

Sometimes building isn't the answer for people.

[elpotro]

?
I enjoy building my AR. First time I ever had an issue with a new built and I brought it here to search for answers and advice... Isn't that what this forum is about? Don't understand the comment.

[elpotro]

Have you done a lock back test? Load one round, fire with an empty mag, and see if the BCG locks back when fired.

I don't see why BCM would replace the BCG since you haven't even confirmed it is the issue. If you do everything Mistwolf says at once you won't identify the issue. I would start with replacing the extractor spring only. How old is the BCG? BCM had a run of bad extractor springs a couple years ago.

I will do everything Mistwolf says. I already bought the Sprinco extractor springs. I have spare carbine gas tubes and I will change those too. Thanks again to everyone. I will check out now, it seems like my questions bother some people in the forum. Thanks to all for your advice.

[RHINOWSO]

It isn't the questions, it's the failure to apply logic and assume that something (like the BCM BCG) is the culprit when in really you have no clue why your handiwork is failing your. It doesn't bother me, it's more amusing, like watching a monkey try to fuk a football.

Assemble build, test build. Failure? Identify possible causes, check, then test them one at a time.

Wash, rinse, repeat. Minimize variables and changing multiple things at once (unless you can physically confirm they are wrong), otherwise if it magically works, you have no idea what the real problem was.

Then again, I'm demanding of my weapons. I expect them to work, to the max extent possible. I never change anything from a new weapon until I function check it first. Then any time I change any functional piece, it's "unknown" until I shoot it again.

What does that all mean? I get $hit working then I shoot it and stop screwing with it.

But by all means, keep up the entertainment.

[MQ105]

...I went ahead and tried my upper with another lower and it worked fine...

I am confused as to why you are trouble shooting the upper.

[elpotro]

It isn't the questions, it's the failure to apply logic and assume that something (like the BCM BCG) is the culprit when in really you have no clue why your handiwork is failing your. It doesn't bother me, it's more amusing, like watching a monkey try to fuk a football.

Assemble build, test build. Failure? Identify possible causes, check, then test them one at a time.

Wash, rinse, repeat. Minimize variables and changing multiple things at once (unless you can physically confirm they are wrong), otherwise if it magically works, you have no idea what the real problem was.

Then again, I'm demanding of my weapons. I expect them to work, to the max extent possible. I never change anything from a new weapon until I function check it first. Then any time I change any functional piece, it's "unknown" until I shoot it again.

What does that all mean? I get $hit working then I shoot it and stop screwing with it.

But by all means, keep up the entertainment.

Aren’t you a nice humble guy!

10/4