flames out the ejection port during rapid fire ar.

[thegoose]

Ok so I was throwing lead down the range and during rapid fire I was getting flashes out of the ejection port. What could the cause of this? It's an hbar with an 18 inch barrel.

 

[PapiBarcelona]

Unburnt powder?

 

[thegoose]

Is this normal for an ar that is just getting broken in?

 

[dreadpirate]

I have never seen that. What ammo are you using?

 

[thegoose]

Pmc

 

[mopar92]

Upper style?
Maker?
Parts?
Factory or Home Build?
Ammo?
BCG Manufacturer?
Gas system?
Buffer?

 

[dontpanic]

Pretty normal. You just need the right light (or lack of) to see it.

Normal for flash, not flames

 

[thegoose]

Just a flash. Noveski upper. Fn barrel, fish bone flash hider, ccmg bcg. spikes lower.

 

[Cyclone]

yup, DI direct impingement... its the gas that travels to your gas tube to push the BCG. its visible sometimes...

 

[thegoose]

Cool, thanks guys!

 

[BenL]

yup, DI direct impingement... its the gas that travels to your gas tube to push the BCG. its visible sometimes...

^ This.

If it was too much (overpressure during bolt rotation), the bolt wouldn't release and the gun would lock up. I had this issue with a 50 Beowulf during rapid fire; every 5 or 6 rounds, the bolt wouldn't release. I just changed the buffer to a heavy buffer to slow down the pulse slightly (give pressure an extra fraction of a second to drop a little), and it fixed the problem.

 

[Clem]

I was also thinking you might want to weigh your buffer. If it is the standard 3 oz. you might want to consider increasing the weight. They come in a bunch of weights up to 5.4 oz.