Id say you're right ackleyman.Ive shot hundreds of groundhogs in the hot summer sun for years using h380,loading 55 grain nosler for .243 at around 4100 fps.,never had any problems.If I could see it ,it was dead!!!My farthest shot was 532 yards,hit the ground hog,found blood but got back in the hole.Never shot it much in the winter for coyotes fox and such,but I wouldnt think cold weather wouldnt affect it any.As far as varget goes my brother has 2 different 22-250's and could not get any groups out of varget worth talking about ,thats the reason I Havent tried varget.Thanks for everybodys reply,Chad