http://www.hodgdon.com/data/youth/20remrxpsts.php

I use the downrange versalite clone of the waa 20 (drv-20) and get good crimps on a mec 9000. This is only one of many light 20 loads, a good source for reloading info is @ http://www.shotgunworld.com/bbs/index.php. Search for 3/4 oz loads and you'll find a wealth of useful information there.