Welcome to the GTA Forums Christian !
You have found the BEST AirGun Forum on the Internet ! And, A GREAT PLACE TO BE !!!!!
RWS makes a very good airgun, and cleaning the goo from the barrel is recomended, however don't use a metal brush ! Many of us use a length of weed whipper line, run it down the muzzle of the barrel, attach a proper sized patch, add a drop or two of Goo-Gone, and gently pull it through the barrel. Do this two or three times, until the patch doesn't show barrel oil on it, then run dry patches through until dry, also two or three.
RWS rifles have been coming out of the factory without proper lubrication, and a GOOD Tune will make a world of difference, even in a great air rifle. The insides will be cleaned out, The burs inside your airgun will be removed, andProper lubes will be added to all the right places, your gun will shoot smooth and consistently. A Good Tune, a Turbo Tune, is highly recomended !
Let us know how you make out !
Bill