TRADITIONS XBR POWER LOADS .27 CAL 100 PK. Traditions XBR Powerloads made specifically for the Crackshot XBR and are the only load you should use in your Crackshot XBR rifle. The XBR Powerload is .27 Caliber Long and is used to propel the Firebolt arrow out of your XBR. Comes in a pack of 100.