10.3 DD with A5 system

[HD1911]

He also noted that was dimpled for MK12 gas block... would that be the issue? It has a BA gas block... doesn’t add up but...

So is it dual dimpled or just a single?

[elpotro]

So is it dual dimpled or just a single?

It is dual dimpled... I will go out and test on another lower and I ll get a regular Rifle Spring. I hope is not the BCM BCG. I had a bad experience with a BCM BCG once but I attributed to bad luck... but now I am wondering. I have other BCG for spare... I will keep you all posted. Thank you for your help.

[MistWolf]

Please describe exactly what your AR is doing.

For example, is the BCG not moving at all?

Is it the AR extracting the empty, but not far enough to eject?

Is it extracting, ejecting but not loading the next round when the BCG closes?

Or...?

[elpotro]

Please describe exactly what your AR is doing.

For example, is the BCG not moving at all?

Is it the AR extracting the empty, but not far enough to eject?

Is it extracting, ejecting but not loading the next round when the BCG closes?

Or...?

MistWolf

The case extracts at approximately 3 or 4 O'clock but the next round does not load. Every once in a while it will load and others it will jam, but for the most part I have to shoot it like a bolt gun.

I already disassembled the upper checked the Gas Block. I did notice that the BA gas block aligns perfectly with the dimples of the DD barrel. I am going crazy here... I am starting to think way out of the box... maybe the trigger hammer is too big LOL! In all seriousness, my next step is to go with other lowers and begin trying lowers, springs, buffer weights combos, etc...

[prepare]

MistWolf

The case extracts at approximately 3 or 4 O'clock but the next round does not load. Every once in a while it will load and others it will jam, but for the most part I have to shoot it like a bolt gun.

I already disassembled the upper checked the Gas Block. I did notice that the BA gas block aligns perfectly with the dimples of the DD barrel. I am going crazy here... I am starting to think way out of the box... maybe the trigger hammer is too big LOL! In all seriousness, my next step is to go with other lowers and begin trying lowers, springs, buffer weights combos, etc...

Same results with multiple magazines?

[elpotro]

Same results with multiple magazines?

Yes, same result with multiple magazines. Could it be that the Ballistic Advantage Gas Block does not align with the DD barrel gas port? I know it seems like a dumb question but I am trying hard to figure this one out. I disassembled everything and there was a perfect ring around the gas port in the barrel indicating gas coming through. Sorry for all the rambling. I really appreciate everyone trying to help here.

[prepare]

Yes, same result with multiple magazines. Could it be that the Ballistic Advantage Gas Block does not align with the DD barrel gas port? I know it seems like a dumb question but I am trying hard to figure this one out. I disassembled everything and there was a perfect ring around the gas port in the barrel indicating gas coming through. Sorry for all the rambling. I really appreciate everyone trying to help here.

Remove the gas block set screws, rotate the gas block until you see the gas port centered in the set screw hole. Now, is the gas block in the same position other than being upside down?

[elpotro]

Remove the gas block set screws, rotate the gas block until you see the gas port centered in the set screw hole. Now, is the gas block in the same position other than being upside down?

Ok, I did that, and yes the set screw hole aligns perfectly with the gas port. I went ahead and tried my upper with another lower and it worked fine. I changed the green sprinco with for a regular rifle spring and I did a one round test. It was locking only with the A5H0. It shot well unil suddenly I had a double feed. In short... this is not a reliable system... I will continue to tinker with it but no luck so far. I will go ahead and buy a DD MK12 gas block. I did not want to spend $70 for something I could get at BA for $20... but now I am troubleshooting. Does anyone know of a MK12 Gas block that is not $70?

[elpotro]

Could it simply be that the gas tube came defective?

[MistWolf]

...It shot well unil suddenly I had a double feed...

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.