You can put some lube on the extension when installing the barrel.
I would make sure it was tight but not farmer tight.
It does not to be baby huey tight.
The carbine stock/buffer should work if that is the stock you want to use.
I have a adjustable gas block because the hole was drilled to .110 diameter.
It did not do much.All of my other rifles have a standard gas block,you will have to shoot it to see if it is gassed right.
Hope this helps.
