Ah, thanks! Nice gun.
Oddly enough, I’d be happy with an 18-19” barrel for this app, but I don’t recall seeing any 9mm rifle in that length. Might not have worded search on local seller’s website well.
From what I understand, 16" is the optimal barrel length for most factory-loaded 9mm cartridges. After that, there is no velocity improvement. I know that with a 16" barrel, mine visibly pounds steel plates harder than any 9mm handgun. As I also mentioned, I can hit 8" plates at 200 yards with the red dot sight I have on it.