Last week I was out shooting my most used M4 at a FDCC event in the pouring rain. I've had this rifle for about 5 years, there's a lot of rounds through it. I would have to guess from the classes and competitions and the cases of ammo I have bought, between 14,000 and 16,000 rounds all in all. So I wiped the gun down with a towel before packing it up, but when I took it out of the case, the parkarized barrel had a little orange tint to it. So I decided to completely strip the gun down and give it a better cleaning than it has ever had.

Once I had it all down, I decided to take the gas tube off as well to clean it. I was amazed at how much gunk was built up in the gas tube hole in the upper. Gas tube is very discolored. As I was cleaning it off, at the front sight end, I noticed a small hole on the opposite side of the hole thats supposed to be there on the underside of the tube.

At first I was surprised that the gun still ran, and I wasnt having a problem with low gas, but I suppose the hole didnt do much. It was under the front sight and probably covered over with crud. So I suppose that would have stopped and gas leakage the hole would have caused.

I have no idea how long the hole was there, I have never taken the gas tube off this rifle. Needless to say, I replaced the gas tube upon assembling the gun. I was just surprised to see it and surprised it hadnt caused any problems.