-Load up the rod properly, and you should be all right.
-I’ve casted up to 24oz on a heavy rod but it was a side-arm, off-the-ground lob cast on heavier rods (like an Ugly Stik) 20-40/30-60 rating. Long-casting up to 8-12 ounces.
-You are NOT trying to whip the rod forward as hard as you can; you are using principles of leverage and physics to project the weight forward.