When the Rage heads were first introduced I purchased and worked with all of them, in the entire range of of grain weights availible, for about a year. The only ones that didn't "squiggle" at the end of the cast were those under 450 grains, when used in conjunction with SFS poly leaders and unweighted, or lightly weighted flies.

I came to the conclusion that in the heavier grain weights (extra belly length), the added weight in the rear didn't pair well with the front taper length and final tip diameter? I intended to chop off a couple of feet from the front of the 480 or 510 to see if it would remove the squiggle effect, but ended up selling them all before I got around to it.

In looking for replacements I cast a few other scandi and hybrid type short heads, settling on Buelah Elixr's. No squiggle was what I was after, regardless of whether or not the fly was still fishing at the end of the cast. (Nexcast WA's are also smooth casting.)

Try a 10'-13' SFS poly leader or type 3 Delta tip on your Rage and see if either one helps. Good luck in straightening out the squiggles.