...your rifling looks good...however it takes better equipment to look at the throat of your rifle, which is equally, if not more important...had a 7mm that i loaded very hot all the time...somewhere around 2,500 rounds the groups started opening up until it became spread all over the target...turned out being that the throat was burned out...wound up rebarreling the gun...the rifling still looked good...you need a bore scope to inspect throating...but if you are getting decent groups then not to worry unless you want to have it checked out...
best