So to simplify everything.
1) Do you have adequate air? Y/N
2) Do you have the LPR set high enough? Y/N
3) Do you have the timing approximately right (enough that the gun will cycle)? Y/N
4) Are you certain of where the leak is? Y/N
If you didn’t answer yes to all of the above then you need to go back and fix those issues before moving on. After you are able to answer yes to the above
5) Are you using a hinge or slide frame?
6) Does the leak go away when you pull and hold the trigger? Y/N
7) Does the leak move from one vent hole to the other when pulling and holding the trigger? Y/N