Norinco Jw 21 Rifle Manual

Hi guys
I have a Norinco JW 23 ( ? ) that I bought new about 15 years ago.
Shoots ok with 40 grain projectiles, never grouped the lighter 30 (?) projectiles anywhere near as well
@cambo did a write up afew years ago that inspired me to polish the bolt, and generally do what I could to get it shooting better. Action is glass bedded. Barrel floated. I tried a pressure point on the barrel, made no difference.
Shoots about 1.5 to 1.7 MOA with the 40’s.
I know that the 22 mag isn’t an inherently accurate round, but what level of accuracy would you expect ?
Now as I have 2 22’s and a 223, the magnum hasn’t left the safe in a couple of years.
Am I chasing shadows ?
Is it worth chopping the barrel to 18” and running a suppressor ?