Aaaargh, birdnests, you're getting a really great finish on aluminium and then the swarf tangles up, gets trapped, and badgers the finish. Been there, done that. 
The SCLCR code is for a toolholder rather than for inserts? The CCGT inserts for aluminium in SCLCR holders work well, but to get proper chip breaking you need to be running at high feedrates. Try a feedrate of 8 to 10 thou per rev. If you get the feedrate correct the swarf should curl towards the front of the tool, in the direction of cutting, and break into small pieces.
Andrew