ORA CQB is 35 yards and down, barrel length is not really a factor especially if you are using some sort of optic.
This season several competitors did quite well with short barrels, as did others with 20" and maybe even longer barrels. I used a 14.5" barrel because that is what I already had.
One of the things I learned is that in CQB (as in many other things) there is no substitute for reliable equipment and the skill that comes from practice.
Hundreds (maybe thousands) of points were lost due to jams, bungled reloads and an endless variety of stupid mistakes. And that was just me...
So whatever you choose make sure it works and that you know how to run it.
Snapshot