The problem is that a few have not dropped in place. The last two a squirrel (disappeared into the underbrush) and a rabbit (kicked for quite a few seconds) were hit square in the chest. I originally started thinking I needed to adjust my power, but I've looked closer at the varmints I've taken down lately. And all were really DRT even though they didn't drop immediately.I'm using JSB Match Exact Jumbo Heavy Diabolo 18.13 gr .22 cal pelletsA quick post mortem showed that the rabbit was hit exactly where I thought, the pellet would have gone through more than likely the heart and part of a lung and came out the back. Slight downward trajectory, I was seated.This does not match up with my previous results. I haven't changed anything. Haven't changed aim point. The only thing that has really changed is the ambient temperature. Maybe that has made the critters tougher?Opinions -