Here's my Winchester 94 story.
My grandfather hunted every winter from 1950 until 1965 - with the Winchester Model 94 30-30. He gave it to my dad around when I was born.
In 1975, when I was 10 years old, it was the first rifle larger than .22 I ever fired and it knocked me on my azz. It's a good wallop, the 30-30.
By 1985, I was carrying that same model 94 in a soft case on my back while riding my bicycle through the suburban streets of Long Island on my way to the Mitchell Field indoor range, in the center of Nassau County.
By 1995, I had been using that old 30-30 for 20 years - and never had a scope on it. For me it became just "the rifle" and I learned how much to hold over a target and how to sight it and I got better and better with it.
In 2005, in my 30th year with the gun, I went to a Turkey shoot. This is an event where you have a domestic turkey in a box 100 yards down range and all you can see is it's head sticking out. You pay $1.00 a shot and if you kill the turkey, you win it for Thanksgiving. (they don't have them anymore, some folks seem to object to the contest for some reason).
I showed up with my iron-sight 30-30, and my buddies there openly laughed at me. They were all set up with a whole bunch of scoped rifles (had to be .243 or large, max 9x scope).
In what has since become a legendary shot, I stood, cocked the gun, held my breath, waited until I was just right - and took the head of that bird clear off.
Thinking it was a lucky shot, the guy next to me offered me $100 if I could do it again. Once he showed me the cash, I lined up, and did it again. I gave the $100 to the gun club and the turkey to him.
Never underestimate what you can do with enough practice with ANY firearm.
Unfortunately, I no longer have that gun, and in the last 3 years, my eyesight has taken a dramatic turn for the worse, and I think that I'll never make that kind of shot again. I know the gun is in good hands, having returned it to my Dad when he moved down south.
Anyway, I've become convinced that while the gun matters, your experience with the gun matters much more.
And I'd suggest that lots of practice with 30-30 is a LOT cheaper than with slugs!