Vall,
The flats are integral to the barrel and Morris created them on a 1.300" barrel blank using the HAAS CNC.

The Model 70 is a .375 H&H Mag and that barrel started from a large diameter Marquart blank. The barrel is a full ovate incorporated into a octagon that transitions to a round. It too was created on the HAAS and has an integral front ramp. sling stud, recoil lug and quarter rib.

All of the other barrels were also profiled from large round blanks on the HAAS.

Dennis