Lots of practical responses from a bunch of addicts with an expensive out of state elk hunting habit.
I bought my 7mm 25 years before it ever got to shoot an elk and it works well for deer, maybe the best deer rifle but your Whelen has the advantage for elk killing out to 200 yards certainly.
If you don't already have them good boots, binoculars, rangefinder will make a bigger difference in your experience and chances for success.
A little longer range practice should give you a better answer for your rifle and scope combination. Whatever range you can consistently hit a coffee can sized target from a field position gives you a safe conservative maximum range. If the Whelen does it out to 300 you are probably good to go.
Our area offers more long range shots than close up normally so we practice out to 800 getting ready for 400 -500 yards. In a different area my first bull was only 60 yards away and closest cow was 11 yards when I pulled the trigger.....you never know so a rifle you use like it is part of you.
