Thats a bad group for that gun at 100 i would try cleaning and if dont work get the better liner, i have quite a few pcp and i have one 600 bucks no reg gets a better group you will figure it out and good luck
Good luck and if you need anything else hit me up because i ripped my apart and did all custom work to mine any help just ask and if unsure of something deff ask we done want anything bad to happen to you lol
I tried them all and they worked great i just liked the aluminum one because it was aluminum and i had so much power anyway 100 fpe shooting slugs it was good enough for me i even dialed back a little