mehavey,
AR15s are not great for a wide range of loads; they are gas operated without adjustments, and they have extractor and ejector features in the bolt face.
Sometimes they seem to stretch brass on extraction.
Ruger #1s are different. They have breech faces with only a firing pin hole.
They will extract anything, and do it after the brass has cooled for a second.
Maybe that accounts for some of our differences.