Ballistic Advantage 11.5 Malfunctions

[young_gun]

I just put together an 11.5 pistol and took it to the range today. It’s not my first build but it is my first pistol

Ballistic advantage carbine gas 11.5 barrel with fsp
BCM BCG
H2 buffer
PSA LPK (I know)
SBA3 and normal carbine receiver extension

I was getting consistent failures to eject that were causing double feeds and even a bolt over base when I used Federal M193 no matter the mag (Pmag M2/M3 and Okay USGI)

Russian steel case worked better but still multiple malfunctions of the same type per magazine.

I performed a lockback check and it locked back every time. One interesting thing I noticed was that when I fired the gun without a magazine inserted, the brass fell out of the magazine well. I only did that one time though.

The gun was lubed but not dripping

Brass ejected at 3:30-4:00 with steel and 1:00 with M193

My guess is that it needs a heavier buffer and possibly an extra power spring too. I emailed Ballistic Advantage and they told me to start with a carbine buffer and figure it out from there but that seems like a waste of time.

What do you think?

[themonk]

I agree that the carbine buffer is a complete waste of time.

Did you try a different BCG?

Hows the fit of the gas block? Look good from an alignment standpoint?

What is the buffer spring - just standard carbine buffer spring?

[young_gun]

I agree that the carbine buffer is a complete waste of time.

Did you try a different BCG?

Hows the fit of the gas block? Look good from an alignment standpoint?

What is the buffer spring - just standard carbine buffer spring?

I didn’t try a different BCG but I will tomorrow.

Gas block is pinned from the factory and looks straight to me. I was able to zero the gun so I doubt it’s out of alignment. There doesn’t appear to be any gas leaking at the gas block either

Buffer spring is standard carbine spring that came with the LPK but I also used a BCM spring but it didn’t help. I tried an H1 buffer too but that did nothing to help.

The gun locked back every time and feels more overgassed to me than a midlength so I don’t think it’s a problem of not getting enough gas

[MistWolf]

Replace the extractor spring with one from Colt or Sprinco.

[young_gun]

Replace the extractor spring with one from Colt or Sprinco.

Extractor spring is a five coil with the black insert but no o-ring and it’s from BCM (it’s got a brand new BCM BCG) I was under the impression that BCM’s were on par with the Colt ones.

What makes the Colt or Springco ones different or better?

[gaijin]

Sounds like an extractor problem.
Agree with “try a different BCG/extractor spring”.

[joeg26er]

I doubt anything is wrong with the bcm bcg
Might be an issue with the buffer tube extension alignment or the buffer retaining pin

[prepare]

Did you try a different magazine?

[young_gun]

Did you try a different magazine?

I tried 10 different mags. Gen 2 and 3 pmags and four different USGI mags. All mags worked in my 16 inch gun that I also brought with me

[CoryCop25]

Start with the Bolt.
Add the O-ring
Colt or Sprinco extractor spring is a good idea for any of your BCGs
Use a different bolt
PSA action springs are not a good choice

I don't think its the buffer. If you're tossing Wolf ammo at 4:00 and true 5.56 ammo at 1:00, this means the 5.56 ammo is hitting the brass deflector on your upper and the Wolf ammo is too weak to make it to the brass deflector.