.22 fx t12 with smooth twist barrel - best longer range pellet ??

.. hey yall , happy holidays ! a good friend left his .22 (5.5 mm) fx t12 mk2 synthetic with smooth twist barrel - what is the best longer range pellet yall have experienced thru this air rifle ?? the gun is bone stock - fills to 220 bar ... this will be a 50-70 yard critter getter .. i'm guessing 18 grain jsb's , and barracudas -- but i know nothing about the smooth twist barrels , and needed an excuse to bug yall (jk) .... also these dont have regulators, but can the power, shot curve and shot count be adjusted -- like i did for his .22 benji woodswalker ?? pastor loves that little camo carbine now ... but back the fx t12 ; i'm also guessing the shot count to be around 30 .. anything i can do to make it quieter ? please reply .. needed yallz advice and experience with this gun before i can order pellets.. thanx. - paul.
 
18 or the 15.89 JSBs are going to be your best bet in that rifle... Maybe even some Hades! Not sure if that rifle has a hammer spring adjustment but you can get out the chrony and find the sweet spot in the fill pressure for a good shot curve....most of those non reg guns have a favorite fill not always the max ! I had an older FX cyclone smooth twist and it loved both pellets I mentioned..

James from Michigan