Been playing bolt ons until I got a Rickenbacker 4003 recently. Thing is, I cant get even low action from the first to last fret. On most of my basses, the saddles will go low enough and with some amount of relief the bass plays really well. On some occasions when the saddles cant go low enough, Id just add a shim. Problem solved. I cant shim my neck rick though since its a neck through and it irks me that I cant set it up low. Is filing the saddle my only option now?