Whats wrong with my airsoft gun?

I own an Echo 1 M4 SPC Version 3. The barrel had a 2-3 centimeter left to right twist. I used the barrel wobble fix to help the issue, by tightening the delta ring base, and adding a strong glue to the casing of the inner barrel and sliding the outer barrel back on. It seemed to work just fine, everything is lined up, but my FPS is MUCH lower. I'd say by 50-75 FPS. I needed to turn the hop-up on about 3/4 of the way to full hop-up just to get horizontal accuracy at less than 100 FEET! What went wrong?