hey im new here and to rc tanks

i just got a hen long tiger 1 tank for christmas and it works fine but when i use the gun, it just makes some noise then it stops. If i keep shooting it continues to do this until all the pellets i put into the turret come out in one go, getting stuck in the muzzle. So i tried to just shoot one, but that didn't work either, and if continue shooting it will eventually pop out the end and get stuck in the muzzle. Now, these are the bb bullets that came with the tank, so they should fit the barrel. I got no idea how to fix it, although i think it may be happening because the whole barrel itself can move side to side, and the right side of it can come out far enough to see the loading mechenism. im thinking of taking it to the local hobby store but they reckon it will cost $75 to fix, and considering the tank only cost $130, im not willing to do that.

other than that it is a great tank, ive chased many a stray cat thats come to investigate it.