how is your product wall thickness, if they are uniform, different part wall thickness has different shrinkage. The best way is to make it uniform and you can get desired part shrinkage. if it cannot be, make steel safe will be the best way to resolve it. do you run moldflow to evaluate the part defects. if the tool has enough cooling to make part. We can provide engineering service to help you resolve it, please contact me if you would like to .