M16 Having Firing Issues, Not Feeding Reliably.

[Rheed]

I just arrived home from vacation and was greeted with my package from weapon blender. Inside was a new bucking for my M16 since the old one was torn. So I go through the steps of installing it. I think I must have made a mistake along the way or something because now it will not feed when I hold the gun properly. The first few rounds will fire if I hold it upside down however. I have no clue what the problem could be, this is on full auto, as the M16 came from Spetz in a trade and had no semi-automatic. I do notice it is cycling quite quickly, so it could be that it's cycling too quickly? But I can't shake the notion that I did something wrong when I installed the bucking.

[All American]

I've had this happen to me ALOT when I would repair or fix up guns that needed their bucking replaced. Usually the problem was the bucking was either pulled to far up the barrel or not put on tight enough. In your case it sounds like the bucking might be a little bit loose and blocking the bb's from entering the hop-up chamber. Look into your M16's hop-up chamber and check if you can see the bucking if you can than it is probably on too loose and you should try redoing it. Also putting silicone oil onto the hop-up bucking will help you place it into you hop-up chamber easier without it moving too much.