The barrel is too skinny
So it needs the band if you've got anything on the end of the barrel.
The downside is; it's easy to knock the muzzle on something and find youself shooting a dot to one side halfway through a comp. The grub screws don't hold the band in place firmly enough.
Your options are:
1) Stiffen the barrel somehow.
2) Attach the barrel band to the end of the air cylinder more firmly.
3) Free float it and have nothing on the end but live with the noise.