I've often wondered which was best. I recently got a Marlin 795 (22lr semi-auto).
And even with a decent scope, I can only manage a softball sized pattern at 100 yards.
I did the whole "try each brand" method and some ammo was more accurate than others. But still couldn't pull a five shot group smaller than a softball.
All the ammo worked fine except for the Remington...which failed of course. I ended up with multiple FTF and one dud.
So I'm not sure if it is the rifle (which I'm thinking it probably is) or the ammo.
I even had other people shoot it so I could eliminate myself as the point of failure.
To contrast, my Ruger MK II has never given me grief and can make excellent patterns (albiet I've never shot it out to 100 yards
)
So I'd say it isn't always the ammo. Sometimes the rifle just sucks.