Haven't found much that was quiet and accurate at the same time
If you can find CCI Quiet then get as much of it. Full 40 grain round in the 670-700 FPS velocity ranges sounds like a pellet gun,..... except for the fact that it carries almost 3 times as much weight as a typical 14 grain .22 pellet.
Chronographed, I saw not too much of a standard deviation, but one shot out of 5 or so rounds would come up with a spike in velocity increasing the overall FPS spread to a high margin.
I might say that your tight 5 + shot groups isn't something you can expect Anywhere near a consistent basis,.... but you might be able to expect 2-3 MOA easily at 50 y. Quiets can be quiet in a long barreled rifle, but still have a bit of a crack in carbines. They however are probably the best over all low decipel pest/ varmint rounds for intermediate rimfire ranges- 20-50 yards max.
Mike