AR ejection patterns

[cmshoot]

A better way to understand it is carrier velocity. The overgassing causes high carrier velocity, while undergassing causes slow carrier velocity.

Springs need time to work. If carrier velocity is too high, things happen prior to ejection.

The chart below can be fooled by the deflector. If you are getting marks on the deflector, the location of your brass pile is not a true representation of the direction the brass is leaving the ejection port.

 

[Bennyboy]

So what is acceptable marking on the brass deflector? None at all?

 

[cmshoot]

So what is acceptable marking on the brass deflector? None at all?

I want none at all, but depending on the ammo you’re using, it’s always possible to get some markings. If you get an “out of spec” round in a “perfect” gun, you could end up with brass bouncing off your deflector.

 

[Freshly Minted Georgian!]

Nice, helpful cmshoot

 

[cmshoot]

Just because your gun is running doesn’t mean there isn’t a problem.

 

[ncrinc12]

I have a 300 bo sbr build that when shooting with a can, the brass is hitting the deflector every round. Does that sound like a gas block adjustment?

 

[Bennyboy]

I want none at all, but depending on the ammo you’re using, it’s always possible to get some markings. If you get an “out of spec” round in a “perfect” gun, you could end up with brass bouncing off your deflector.

My 14.5 mid length BCM with A5H2 buffer and standard A5 rifle spring has some on the deflector. I was planning to order a Sprinco Green spring as a replacement anyway, but would the A5H3 buffer be a better choice?

 

[cmshoot]

My 14.5 mid length BCM with A5H2 buffer and standard A5 rifle spring has some on the deflector. I was planning to order a Sprinco Green spring as a replacement anyway, but would the A5H3 buffer be a better choice?

I would keep the A5H2 and go to a Sprinco green rifle spring.

 

[cmshoot]

I have a 300 bo sbr build that when shooting with a can, the brass is hitting the deflector every round. Does that sound like a gas block adjustment?

Putting a can on is gonna amp up the gas system.

How is the brass system unsuppressed, or do you even shoot it unsuppressed?

What length barrel and gas system?

What buffer system?

What gas block?