Pondering upon these rds and this thread. Point being: If you don't roll your own; lot #'s MUST remain the same and the first shot will always exit a bbl of ambient temp.
The importance of this becomes more prominent as the vital zone decreases and increase in range.
A centerfire sporter bbl will not have the same POI at 20F in WY as 75F when "zeroed" in PA; especially when getting "50 cent piece" groups at 100yds without the bbl being allowed to return to "true cold".
A miss should be absolutely be attributed to the shooter. Rimrire precision is more fleeting due to priming and machinery...Always in the back of your mind: "This rd could miss a squirrel's head at 50."