i bought one of those from walmart, too, i liked it so i bought another. have one in .177 and one in .22, and have mostly been working with the one in .177 so far. getting close to 2000 pellets thru it, and it is starting to break in. i could feel lumps in the barrel when pushing a tight patch thru it, and looking thru the barrel i could see what looked like leading. i got out the lead away patches and did a good barrel scrubing. the lumps smoothed out a lot and the gun started to tighten groops. i noticed, while cleaning, that there was like a rough lip at the crown of the barrel. i used a cratex rubber abrasive thingy, no power, just by hand, and turned it against the crown. didn't take much, and the rough edge was gone. remenber, i didn't use the motor, just turned it by hand. so far this rifle has been responding well, groups yesterday were going onti a raged hole, finally. didn't have many flyers either. have found the rifle to be kind of hold sensative, but it is getting to the point that i trust it to shoot where i aim, finally. john