See below from the Sierra manual about the 215 and 250 GK bullets. My guess is you would be fine with the 215 GK out to 200 yards or so as long as you had your muzzle velocity around 2700 FPS. This bullet has a BC of .485 which will give you around 2400 FPS @ 200 yards with 2700 FPS MV. Below that velocity I suspect it will mushroom, but not much larger than caliber diameter. JMHO.

FWIW I have liked Varget in my rifle. Tried H4350, but ES on velocities was @ 75 FPS, and my ES with Varget is @ 16 FPS and better accuracy.

The hardest part about shooting these bigger bullets at whitetail deer is bullet selection. I much prefer the 35's bullet selection for Whitetails you can use the 200 grain Hornady Spire Point or FTX. The 225 Sierra is deadly on whitetails. The 220 Speer Flat Nose is a show stopper you just might want to load it down in a Whelen. For things up to moose and brown bear.... Partitions and Accubonds and even a TSX that should make at least some on here's head explode. Too bad the .35 Barnes aren't 95 grainers or every Barnes fan on ALDeer would bum rush the gun store looking for a Whelen.. All the .35's are geared around Whelen velocities, so nothing crazy. The Whelen kicks like a 30-06 and kills like a 375. The 338-06 is only hindered by having a few bullets geared towards Win Mag and Weatherby velocities mixed in. Not a major issue.

None of the bullet debate really matters at all if you are going to shoot a bear or elk, etc. .338-06 is just a solid round in my book. This is a Ford vs Chevy argument really. Love them both.

The reality is with good shot placement and a bullet that gets expansion at your desired velocity..... it's gonna be "live action" like the Turtle Man said with DRT performance in about any load on a deer.

If you haven't tried some of these big bullets at moderate velocities on deer.... you haven't been living right.

Yep.....great pair 358 Win with 225g SGKs on WT.