Not surprised they were not that accurate. Your rifleing twist rate is not right for a slug that light. You will want to stick with 1oz slugs. Some of the ones that have worked well for me are the Barnes Expanders, and Winchester partition gold. If you have a 3" chamber, and want the best accuracy, you will want to shoot 3" sabot shells through it. I would suggest buying a couple boxes of a few different brands, and head to the range. It is really the only way to find what shoots best in your particular gun. Good luck