I tend to only experiment when I get a new powder. For the most part all my loads are documented and I stick to them. I'm probably not accurate enough to notice if .1 grain makes a difference or not, though I shoot well enough to hit the target easily. I did start experimenting using only the 3 die process for my lead bullets were I seat and crimp at the same time. I still use the four die process on my copper plated bullets. I have changed powers, my wife didn't like Power Pistol in her .380, I switched to Titegroup. I am playing with Powder Pistol in my 357 (not a fan, but found a load I can use). I liked AA#5, but probably will try Bullseye, Titegroup and HP-38, just to find what I like. So I do experiment for a load that's fun to shoot, but once I get it, I pretty much try to stick to it.