About 30 years ago I was hunting a 2000 acre lease with my Dad and Uncle. I had a Glenfield 30-30 with iron sights, and found a good spot where I could have up to a 250 yard shot.
I asked my uncle if I could use his extra rifle with a scope, because I might need it for the longer range.
It was a 300 WM that he used for elk and sometimes for deer.
I sat down on side of the mountain and waited for the deer to come out into a clearing from the fields they were feeding on at night.
Sure enough a eight pointer comes up out of a draw and stops broadside just waiting for me.
I sent off a round, and the deer just jumped and looked around like "what was that?".
So I took a second shot, and the buck ran off.
About 15 minutes later, in the same spot, I went through the same thing with another nice buck. Two shots and two misses.
Again within 20 minutes I had another buck a standing broadside just waiting for me to take him down. Two shots, two misses.
Believe it or not I had a fourth chance a little later in the same spot. Two shots, two misses.
Even as a young feller, I was always known as a great shot, so I just couldn't figure out what the deal was.
When I got back to camp everyone thought I must have killed a whole herd, because they could here that 300 magnum going off over the entire 2000 acres, and they knew I didn't often miss.
I told them what happened, and we all went to bed that night scratching our heads wondering what went wrong.
A couple of months later my Uncle told me he figured out the problem.
He took the rifle out to sight it in for elk, and realized he had never sighted it in for the lighter deer loads he had given me when I borrowed the gun.
The worst part is, the shots were all around 80 yards, and my 30-30 was dead nuts at that range!