Point taken, Tallest; size matters, and needless to say, shot placement trumps it all on any critter.
Since I believe I saw you don't have a range finder yet, I'll stick my neck out a bit here. I think that once you've come to the decision to purchase one, you just may wonder why you didn't get one sooner...and that's just my opinion.
Through the years chasing Wyoming critters, I've used archery equipment, muzzle-loaders (both flint and percussion) and also black powder cartridge in a 45/70 Sharps replica. These hunting tools all served me quite well until my 67 year old eyes started showing me too many front sights, especially in the timber. Once I knew that I'd needed a scope on a rifle to make the best shot I could make on a critter, my old Leupold has served me very well so far, along with how I do my hunting in the mountains for elk.
Now on my deer rifle, another '06, I use a fixed power 6X Leupold out on the plains where I hunt mule deer. I'm really fond of that rig, too, especially out where there's lots and lots of light around the critter. That season starts on the 1st of October, and I just shot that rifle today; it's ready to go. BTW, the farthest I've ever killed a deer with that rifle was just a bit over 200 yards. I do practice with that one, as well as my elk rifle, at a 300 yard target, too. I feel a hunter really needs to shoot at that distance to really see how their equipment works out.
My daypack is my very best friend when out hunting (either on the mountain or on the plains). Everything's in there to take care of me throughout a day's hunt (even if I have to spend a night out unexpectedly), and provides a fine rest when taking a prone shot. Also, it's a very rare thing that I would ever take a running shot at any game animal anymore. My policy is to see the critter first, before it sees me, so I can set up a shot (walking/glassing/spot and stalk; love it). Being retired, I have the time to hunt whenever I want to, throughout the season, so I can be quite picky on a shot on a critter (and pass on it if need be; no problem). And mostly, now, I'm just a meat hunter, so antlers aren't the reason they used to be for me. My wife and I still find the elk and deer the staple of our meat supply from season to season, and it's very satisfying when we can share some of it, too.