Last two mornings I have been working toward setting-up my 250z .22 to shoot 18gr instead of the 22gr I have been shooting.
I intend to use the 250z as my 'everyday' target shooter during the Winter months. My goal was to reduce reg. pressure and improve shot count while maintaining good accuracy with the 18s. The 18s are less expensive so for volume target shooting at 50yds it makes sense to me switching too 18s for the Winter.
I turned the reg. down to 1500psi from where I was running it at 2000psi for the 22gr, Velocity for the 18s was about 910fps at 1500psi. I continued turning up the regulator to achieve velocity change of 10fps each time. I fired several 5-shot groups at each velocity change noting accuracy, and shot-to-shot consistency. Long story shorter, I have settled in on 950fps for best accuracy and best shot-to-shot consistency with either AEA or JTS 18gr. I should mention that accuracy was the worst at 920fps! The rifle didn't like that velocity for the 18s.
I always only fill my 250z to a fill pressure of 3000psi. I was getting 22-shots on regulator with my 22gr tune. Now, I am getting 32-shots on regulator with the 18gr tune.
The 18gr are just as accurate, if not slightly better than the accuracy I have enjoyed with the 22gr. The JTS 18s are ever so slightly more accurate than the AEA 18s. But, considering the JTS are half-again more expensive than the AEAs, I'll be sticking with the AEAs for 'backyard benchrest' use.
I'm done with that..., now what am I going to do airgun related???

Guess I need to get my old self back out calling coyotes!