Whenever you buy a new mag, the first thing you should do is replace all of the orings. That way you know the proper ones are installed and in good condtion. If you use good quality synthetic light oil, they will last for many many years without any issues.
Originally Posted by vintage
If the trigger rod is touching the back of the trigger it needs to be adjusted. It should be about a credit card thickness from the back of the trigger when the trigger is held against the safety with the gun aired up.
The sound you are hearing is probably the burping sound caused by a weak bolt spring. Replace the bolt spring and the problem will probably go away.
Except for the Automag in front, its usually the man behind the equipment that counts.