Benjamin disco air blowback in my face?

Hello guys new to site. I recently procured a Benjamin discovery and am very happy with it. Shoots very well, better than I expected; however, from time to time when I shoot it I feel a small burst of air in my face when I shoot it, is this common or suppose to happen. It's not every shot just every now and then still holds great accuracy thus far. 
 
On my disco the air is coming from the transfer port area. There's a tiny bolt under the pellet probe that holds the breach tight against the transfer port and air tube. Check make sure it is tight... Mine started to blow air out ever since I moved the air tube/barrel clamp forward, closer to the muzzle. Not saying this is the right thing to do ,but I have grown to live with it. Shot string is still pretty consistent and rifle is accurate. 

CJ
 
Awesome help, onto my next dilemma...seems I can fill my discovery up to 2000 and by the next day or even several hours it drops significant air pressure, so I made some soapy water and rubbed around where the male foster fill adapter threads into the air tube adapter and as I expected, it's making bubbles. Is Teflon tape the best fix and if so any specific kind work best ? 
 
I have used just basic Teflon tape you buy from the hardware store to seal tapered pipe fittings. I do 3 wraps around the treads in clockwise rotation (male thread pointing towards you) making sure that you are 1/8" away from the end of the male threads so you don't get any tape pieces inside of the air system. I don't know how to describe how tight to turn it on...you want it tight ,but not too tight if that makes any sense haha. 

Oh before you get to wild...degas the rifle before trying to take the fitting off. I know I know it's obvious , I just have to say it. :)

CJ
 
DEGAS FIRST!!! Do Not do any work on the pressure part of the gun without degassing! Benjamin sells a tool for degassing.
I haven't pulled the fill port on a Disco, but on the Marauder the seal is created by an O-ring, check your parts diagram and see if the Disco uses one, if so, get a new O-ring. Use a little silicone diver's grease on the O-ring.
Good luck,
John