I remember I ran mine with a dual tune for 18.1 and crosman 14.3. The reg was somewhere just under 2000 psi (1800 I think). With the hammer spring adjuster all the way out it shot 14.3 a little bit faster than you were looking for. I think like 910. They were accurate out to 40-50 yards and the velocity from shot to shot was surprisingly consistent as that isn’t an ideal setup to run 14.3. Otherwise my advice would be to run the reg on that gun as low as it will maintain a consistent pressure. I know they don’t run the best at super low power tunes.