AAC manufactured 16" AR barrels

[A-Game]

The barrel is thick enough to make a descent shoulder so I'm going to chop, crown, thread it. I just don't know what length I want to do yet. It measures 0.715 in front of the gas block. I forgot mine when I went to the shop yesterday to measure the gas port. I have the machined pins so I can confirm your drill bit measurement.
Edit: the rear of the barrel measures from as a taper and isn't as thick as an AAC 9" barrel.

[A-Game]

0.81 is the correct size. It was very very tight on the pin when I checked it this afternoon, there is no drill bit to drill 0.80 and 2.5mm makes a 0.82 hole.

[300Blk]

I wish my carbine gas 16" barrel had a gas port of 0.82, if it did I could open it up a tenth or so. Instead it is too large and I am contemplating selling the barrel or just tacking the hole and drill the size I want. I might do that anyway

Actually, I think I'll do that Friday morning before the range session and see if it will cycle the two types of subs I have and lock back the bolt.

The gas post size of the AAC 16 inch carbine gas barrel is not too large. In fact you need to use a C buffer with it as it is.

[300Blk]

I'll be pleased if mine turns out to have pistol gas with an .082" port like yours, so I can open it up until I get the function I want. My current 10" SBR has an .098" port.

It is already the correct size. Don't open it - you will just ruin the barrel. The reason your 10 inch has a 0.098 port is because it is a 10 inch barrel. A 16 inch barrel needs a smaller size because it has more dwell time.

[Netpackrat]

I'll be pleased if mine turns out to have pistol gas with an .082" port like yours, so I can open it up until I get the function I want. My current 10" SBR has an .098" port.

It is already the correct size. Don't open it - you will just ruin the barrel. The reason your 10 inch has a 0.098 port is because it is a 10 inch barrel. A 16 inch barrel needs a smaller size because it has more dwell time.

I agree. I will only open it up if I have the barrel shortened, and it won't function with the smaller port. Not sure what I am going to do with it at this point.

[Netpackrat]

Dredging this thread back up because I am probably going to do something with this barrel soon. Decided against chopping it, and will be building a 16" gun; just wondering what buffer weight I should try first?

[Chedr]

I bought 2 of these a while back and am running both at the full 16".

One of them arrived with pistol gas and one has carbine length gas.

I used the heavy buffer for pistol gas standard buffer for carbine gas theory and both function great with subs or supers.

[Netpackrat]

Thanks for the reply. Been busy and have not been on the forum in a while.