Hey, I have a similar story. A buddy and I were hunting for Sitka Blacktail on Montague Island. I was using my 300 Wby, big for deer, small for the big brown bears. We were out and it was pouring down rain. Could see about 70-80 yards cause it was coming down. Any deer was legal, a deer stepped out from behind a pine tree at about 40 yards. I had see thru scope covers and one in the chamber (big bears, low visibility, remember). I shot, the deer just slammed to the ground and never even twitched. When I got there I found a chunk of heart about three feet behind the deer, it was the biggest piece we found. It was a small button buck. I was shooting 180 Nosler partitions back then around 3000 fps. It rained the entire four days we were there. We hunted all day every day and only saw one other deer. I saw it for about two seconds in between gusts of sideways rain. Everything we had with us was soaked. That little deer sure did taste great!
Take Care