Absolutely- I've been making stock in a pressure cooker for years, using my late mother-in-law's recipe from the 1930's. Put your ingredients in the cooker and cook at 15 pounds pressure for 30 minutes; let cool. Backs and necks are the usual ingredients (plus aromatics), though when I make my next batch I'm going to throw in three of four chicken feet for gelatin.
Don't fill any PC more than 3/2 full; if it's more, it could boil up and lodge something in the vent, and the safety plug will blow and you'll have chicken stock all over the ceiling. :eek: