I have heard of some doing this with 20 cal down to the 19 cal. You may well be able to go on down to 17, but I would think it would be best to do so with a couple steps with a couple die bodies.
Good idea with the Nosler shots.. they are a decent cup and core bullet for our little critter shoots. Bill K
Another idea is just buy the 17 20 grain bullets put out by both Midsouth Shooter and MidwayUSA ( varmint nitemare/dogtown ) they are nothing other than the Nosler shot, with their names on them. and already to go. Except they do not come in a heavier weight, which appears to be what you are after.