Hi to all, I have build lowers but never an upper. I have a .300 AAC with a factory pinned gas block like the picture, I am going to use with an Aero M4E1 enhanced upper (pistol build). I just realized I am going to have to unpin the gas block so I can get the barrel nut on.

Best way to unpin this gas block?

Two set screws clearly have to be loosened, drive the pin out from left to right??  Left to right defined as when looking through the barrel, looking down the breech out the muzzle, like bore sighting?

What tools are needed, Geissele gas block punch set, and? hockey puck from Brownells, or??

Anyone unpin a Ballistic Advantage or BA Hanson barrel, I have read the pinned Noveskes are %$##@!

Just drive it out with the proper punch. Took my BA block off in the time it took me to type this.

Curious, what do you use to support the GB? That's the biggest challenge, I've found, given the rounded shape.



I have a delryn gas block holder that works great for the gas tube pin, but doesn't do squat for the barrel pin.



-Stooxie



 

My BA barrel is pinned with a roll pin (sometimes called spring pin) and can be driven out either direction.



Drive the pin out first them remove set screws.  You could do it the other way without hurting anything.






Just support the gas block with something solid like a piece of wood and drive it out with a punch.  You don't really need a special punch but roll pin punches are made to help keep the punch on center.



 
 

Thanks to all for the input, greatly appreciated.

Best gun plumbing tip I ever got regarding gas blocks is this:

Find a nice thick piece of carpet scrap.  Put the barrel on it and then use the proper punch.  The carpet supports everything, cushions the parts, and allows the pin to fall out without having it get lost.  
It works like a charm.

I use a block or something of that nature to prop the gb on to keep it from rolling.

I measured the pin, it reads .122 on one side and .123 on the other, it seems to just be a roll pin and I have the Brownells punch kit so I am going to have a go at it after I figure the best way (for me with what I have) to support it.

Thank you, and your M4E1 Upper is freakin awesome, going to buy another!