I can it to move right for bullet operationan and have it in the middle, but it will not go down.   Is this right.  I just got done cleaning it and reassembling it yesterday.

Also,  the gas tube seems loose,  I can wiggle it.   Is this right?

In order to function semiauto,the gas valve needs to be all the way down to the right.To cut off the gas,it is positioned all the way to the left.Not sure why it wouldnt be all the way down,you only have the valve body itself,the button and a spring that goes into the button.Can you post pics of the valve in both positions?If you cant post pics,email them to me at [email protected] and I will post them for you.As to the gas tube being loose,it depends on how loose it is.Too much play there can allow gas to leak causing various jams.