The closest I came to that was with the 22LR adaptor, and shooting some Aguila 60gr 22LR subsonic.

That round was the best shooting of the few 22 LR ammo I tried with the adaptor. I'm thinking the lower velocity, longer bullet, and longer bearing surface helped it in the slightly oversize bore and 1/7 twist.


60gr Aguila group on the bottom target, if I recall, it was 50 yards.
[Linked Image from i.imgur.com]

The launcher consisted of a PSA upper with a 14.7" FN barrel, chrome-lined, 1/7 twist.
[Linked Image from i.imgur.com]