Paparock - if your only concern is whether the 1:38 twist will accurately stabalize the heavy 44 caliber slugs then rather than re-barrelling, which is unnecessarily expensive, just firelap the darn thing and it will shoot fine. Go to the Beartooth Bullets website and read what they do with 444 Marlins and the 1:38 twist and you should be able to see that the twist rate won't matter with the havy slugs. HTH. Mikey.