thekevin: .177 is easily cleaned by pushing (a lot) of Q-Tips through the barrel. Also, you can use a solvent, just make sure you get it all out, and don't put it anywhere near the chamber. Simple Green usually works well also. Take your time, most springers (in my experience) have filthy barrels out of the box.
If your gun is especially noisy, it is likely due to "deiseling." Basically, there is excess lube inside your new gun (I think you said it had 25 or so shots through it?) being compressed inside the chamber every time you shoot. The compressed lube then detonates, creating the loud crack, or at least accelerating your pellets to a speed that breaks the sound barrier. I have two unmoderated NP springers that are capable of slinging H&N Terminators at 1000 FPS, as shown by the chrony. These guns do not "crack," as the pellets are not breaking the sound barrier (1000 FPS and under really "shouldn't" crack). After you clean it, shoot your gun...a lot...and eventually it will settle down as it burns off that excess lube. If after you've "broken-in" your gun it is still loud, start shooting heavier pellets to see if that slows/quiets it down. My .177 really likes JSB 10.34gr domes, and Crosman Ultra Magnum 10.5gr (when I can get a good tin of those, I mean). Best of luck!