New instruments can be hard to assemble. When you try to assemble the different parts, you might experience problems pushing it beyond the cork all the way. This is not necessarily a manufacturing mistake. It is very common that this problem occurs the first few weeks after purchase.
The reason is that the wood will expand at the tenon side after you've played the instrument. As a result of humidity entering the wood the tenon will expand. The receivers metal ring will prevent the wood from expanding but the bore will shrink slightly. Carbone rings might help. Your best option will be to remove a miniscule amount of wood that appears above the cork line. For more information feel free to contact us or visit our webpage. An alternative would be to get our L&P metal joint connection, which has additional acoustic advantages.
Another common problem you might experience is taking the barrel off the instrument after you've played it. The reason is the same. The humidity in the instrument caused the tenon to expand. If thats the case, hold the barrel and top joint firmly in your hand. Watch out not to press onto the side trill keys because you might damage the pads or bend the keys. Press the barrel shortly to the front, back, left, and right until it almost feels like you will break the instrument; then turn it. This almost always does the trick. Be very careful with Greenline instruments because they might break if you do it too hard!