You obviously know what you are doing and what you are talking about. Not everyone here knows that 39.5 gr Varget means 39.5 grains of Varget gunpowder, and that 40 gr Nosler BT means a 40 grain Nosler (brand) boat tail bullet, and that 4200 FPS means this particular load chronographs at a muzzle velocity of 4200 feet per second.
May I ask what you shoot with this load? Varmints? It think it would all but vaporize the top half of a prairie dog.