It is a little more complicated than that. First it will depend on when your rifle was made , early rifles have larger size bores and will shoot best with different bullets than late made rifles . Bore size is important . I once shot a T-97 sniper [ 6.5mm ] in a national bench rest match , just to do it . My best 5-shot 100 yard group was 0.662 , with a total average of 0.894 . Shot with the SI- 140 MK boat tail bullet . There is no Safety reason why you could not use the ELD bullets in any 6.5mm , Swede , Carcano or Arisaka. You may have accuracy problems in some rifles . The Swede would be the best bet for good accuracy with those . There is nothing wrong with flat base bullets either . I have a very early [ 3 digit ] T-38 . It has a .271 dia groove barrel . It will keyhole with most .264 bullets , but has shot 1.25 ish with the .268 dia bullet . So match the bullet to the rifle .