wolf
Was it a factory fit barrel or one you got 2nd hand ? If it is factory , give them a call Tues. AM and explain the problem , i know that they will make it right .
If it was one you got used , it can be tightened up by putting a shim at the point were the underlug fits on to the pivit pin of the frame . try cutting a small peice of soda can to fit and form it into the notch and see if it closes and locks up tight , may be too much or not enough but it is a place to start .
And yes be sure to read the barrel fitting in the FAQs , it will explain it better .
stimpy