I did a quick calculation on just the main "straight" section of a 338LM
1.379 cm ID x 5.12 cm long
=/- .00025 cm" (.0001) ID total of .0005 cm or .0002"
1.379 to 1.3795 ID changes the inside volume from 7.6470 cu cm to 7.6525 cu cm = .0055 cu cm difference for .0005 cm or .0002" variation...