How to pull a perfect offset with 15mm copper pipe 

It’s always between the two MMs on 35 and 45 but not 90. See 90 pull video

James is the guvnor at offsets

Hi. Is it always between the 15mm mark whether it's 30° 45° or 90°?

Ive was also told between the 1 and 5 and in-between the 2s for 22mm....i wonder whether it was designed this way or a complete fluke