Pellet spiralling

Well , velocity is around 620 fps, and my groups at 23 yards are about 3/8's of an inch consistently, I've tried jsb's and the groups open up so the best pellet I've found to like it is field target trophy's and h&n sniper lights Wich groups tighter almost pellet on pellet, but (snipers) haven't tried them at that distance yet, 
appreciate your comment 2d1c
Ruben
 
Rioshooter:
Straightshooters sells a sampler pack of pellets that you can try to see what works for your Terrus. Generally you can't go wrong with JSB's. If you shoot me a PM I can give to some in 14.3, 15.89, or 18.1 gr pellets to try. I also have some crosman 14's that you can have. I never had much luck with springers and have jumped into PCP. I live in Rio Rancho and you can pick them up at my office at your anytime (with some notice). 

Doc