Well, yes- just recalled a thread I started a couple years ago. The thread had to do with group size off bags in comparrison to what that load would do offhand.
At the time, some here said claimed bench grouping accuracy didn't matter much as they were merely shooting offhand.
As I recall, I used my .40 rifle and .400" X .400"balls as opposed to the other group with .395" X .400" balls. These came from the same set of blocks - a DC Lyman mould. I also used LHV lube, 65gr. 3f and .018" or .019" pocket drill patching - very close weave.
The 'round' balls cut a 1/2" group off the bags centered and about 1 1/2" offhand, also centered - both 5 shot groups. The oblong balls made a 1 1/2" group off the bags climbing to 10 o'clock and 3 1/2" offhand - same directional dispersion. Not sure why the climb- but everything else in the load and hold was identical. I shot the bench groups first, then both offhand groups.
The rifle had had perhaps 40 to 50 shots through it prior to the 'test'- with no wiping. At the time, I was quite impressed with both offhand groups, but especially with the best group, bench and offhand.
With large steel targets, either load would have hit every time - however, the accurate load would allow more things to go wrong, than the poor load.
Obviously, barring the odd fluke group, it is impossible to shoot more accurately than the gun is capable of, rather the reverse & usually as a multiple of the gun's capability.