Clean your gun after every range trip....at least pull a bore snake with clp on it through cylinders and barrel. Wipe it down with CLP and a rag . Don't let the crud build up ...the harder it will be to remove later .
357 magnum loads are high pressure, high pressure loads grip the cylinder walls harder....dirty cylinder walls grip even harder , that's why you get hard extraction.
Shoot some target or low velocity 38 special loads, less pressure = easy extraction.
Clean the cylinders after firing 38 specials...every time. Build up will hinder 357 magnum chambering and extraction.
Gary