@DaveJ I like the phrase "know your limit and stay within it"
Personally, I'm not much of a shooter. Yeah I can plink nice groups with a bench rest, but I've never hunted deer from a bench. Standing free hand or resting on a tree, I can shoot decent groups at 100 yards. If I take into account that my heart is pumping from adrenaline, with a deer in front of me, that group is bound to get bigger. It is hard to know how big because I don't get pumped up to shoot a piece of paper, but my accuracy isn't going to get any better shooting at a deer.
At 150 or 200 yards, my free standing or leaning on a tree groups aren't great. Knowing that they will get worse looking at a deer, I choose not to shoot. For me, it isn't the rifle's capabilities that determine how far I can confidently pull on a deer, it is my own.
I have only hunted deer with a scope for the past 4 or 5 years. Up until then it was iron sites because everything I killed was within 50 yards. I decided I wanted to reach further so I scoped out my gun and figured out that 100 yds was pretty safe for me. The first deer I shot through the scope, I watched for some time before thinking "he's not coming any closer" and I pulled the trigger. I paced it off and he was 170 yards when I shot. I felt like an idiot and I liver shot the deer. He was dead within 50 yards, but I wasn't happy with myself for shooting so far and now I'm a lot more careful.
"Objects in scope are farther than they appear"
Long story short, most guns out there can shoot better than I can. I applaud those guys who are rock steady, but I think in general people push the envelope too far. "Know your limit and stay within it!" and don't forget that you will be less accurate shooting a deer than shooting paper!