Yes, it definitely sounds like bolt stick caused by a carrier that is too tight for your powertube oring. You need to get a range of carrier sizes so that you can tune any powertube oring to the proper tension. You should also get an X-valve parts kit. That way you will have a complete set of orings in case anything gets worn or damaged. You don't want to get caught at the field without a way to fix your gun should something happen.
Don't bother adding any shims when you tune your level 10. They cause more issues than they help unless you have a rail that is causing your valve-sear distances to be way off from normal specs.
Except for the Automag in front, its usually the man behind the equipment that counts.