Oh I understand. This is me trading a spare barrel to help a buddy fit a barrel into his atx, his current barrel doesn’t work.Just some data for you. Same ammo in a 16" vs 19" of mine. Only a 50fps difference and that equates to a 30yrd gain in the 19" before a 175 smk goes transonic. Unless that little bit makes a difference for you I'd personally keep the 16.5.