Why would anyone want a short barrel rifle?
My old Marlin Glenfield 60 had a 22” barel, now the same rifle has a 19” barrel. I guess it’s a manufacturing cost thing, because longer barrels are typically a slight bit more accurate.
Short barrels do not work well AR pattern rifles - the 14.5 M 4 barrel is about as short as you want to go for reliability . Using a longer length gas system is good idea even for the M4 barrel
You can go 10 in in 5.56 with guns like the SCAR but ballistic effectiveness drops off steeply
If you want short, go to an FN PS 90 which is optimized for short barrel performance, or go to a bull pup design us has the Israeli Tavor or Steyr AUG
You have one of the good ones.
The old ones with the 22” barrel and the full length 18 round magazine are the ones I look for.