Shortcomings or difference. Small groups isn't what reliable is. Besides the difference unsupported isn't going to be large enough to care.@FL-NC well described above the reality for the shortcomings inherent to all other designs behind the AR. Keeping an AR running smoothly isn’t so challenging, but getting any of the others to adapt in the same ways as can the AR, or getting them to shoot as small, are largely just pipe dreams.
Bench shooting isn't a real world test.
I prefer the easiest to clean. AR's are a real pain compared to a Garand type action.
Reliable is a loaded question.
And which one is easiest to get spare parts for. Ar's are mostly different and M14 parts kits aren't on the back page of every magazine now days. I haven't the answer but it needs discussed.
I have spare parts for Garands ,AR 15 and Glocks but nothing else.
I'd rather have a .308 Garand next to the front door than anything else. They are cheep enough from the CMP to purchase a pair.
I don't consider my SFAR or the LAR8 forever guns. But I'd trade off my 06 Garands for .308
Expert grade obviously. For a forever gun that is.