For help stopping threats Winchester PDX1 Defender .22 Magnum 45 gr JHP Rimfire Ammo - 50/box is an excellent choice. The unique bullet design is able to provide optimal penetration as well as maximum expansion. As the JHP within the name implies the bullet is a jacketed hollow point offering this penetration and expansion.The .22 Magnum is the only option for the PDX1 defender and as the ammunition was specifically designed for personal protection you can trust that the 45-grain bullet will get the job done.