I removed the Vortek kit, inspected the comp tube and piston seal for damage and installed an ARH spring kit with the OE piston liner. Test fired without a scope and the gun sounds normal now. Ten shot string of 5.53 FTTs, 735 fps ES 12 and SD 3. That's 17.58 fpe. That's about what I remember that kit doing last time.

Assuming the noise doesn't return I'd have to think the noise was from the Vortek steel outer guide resonance. I have to do some more testing with a scope on it.

Thanks all for the help
Ron