You don’t need a bigger gun, you just need to keep practicing at a mile. The further you go, the more critical your wind reading skills become.
My .243AI/105AM has outshot a .338LapuaAI/300Scenar at a mile, due to shootability, familiarity with the load and DOPE, and the ability to easily spot shots through the scope due to much less concussive blast at the shot.
