Originally Posted by 88_gurgel
I am getting some blow by around the gas tube on my AR between the tube and the block. Is this a normal thing? It hasn't caused any operation problems at all. Is there a seal or is it a press fit?
I am not too concerned with it but just wanted to know if it was normal.
A little of this is probably normal. Is the rifle new? If so, it means the seal between the the gas tube and the gas block is not quite perfect. Since it isn't interfering with weapon operation, I wouldn't worry about it right now. There is a good possibility that over time, carbon buildup inside the gas block area the tube mates into will seal the leak anyway. If it does, it is still no threat to the normal operation of your weapon. The only time it will bite you at that point is the next time somebody has to yank that gas tube out (most likely in connection with a barrel replacement), but even then, it's the gunsmith who will be putting up with that, not you.