What magazine do I need for a Tikka T3/T3X Long Action (LA)? Below is a list of the long-action AICS metal magazines size you will need for a Tikka T3/T3X Long Action, depending on the chassis you purchase. LSS - 3.560" TAC 21 - 3.560" LSS-XL - 3.560" ESS - 3.560" HNT26 - 3.560" Oryx - 3.560"