Not a gun writer but, you’re talking about one of America’s favorite .30 bullets…for deer. If I was thinking about using them for Elk, I’d use your exact setup. In my opinion, you’re within the Goldilocks zone of performance (velocity vs impact range) for broadside-ish shots to just about 300 yards. I’d personally have total faith in these tough 150gr bullets, inside of 250-300 yards depending on angle. Your confidence in the bullet is important too. Remember many elk are killed with the wicked little 6mm rounds every year. You’ll be fine!

Show us the pics when you get back!