I purchased a Hornady Magnum Sonic Cleaner & they are giving 100 free bullets. I load 9 and 10mm FMJ's & have no knowledge of the following: 9mm .355 115 GR HP/XTP 10mm .400 155 GR HP/XTP Any reason to choose one over the other? BTW: I would want to use either Power Pistol or Longshot. Alliant has a recipe with PP for the 9mm but not the 10. Thanks!