Here's a fix for the portal gun being off-centered from the hand

[MTNdew4]

You should add a line to the page along the lines of "use the console to adjust the viewmodel offset of the Portal gun with viewmodel_offset_x, viewmodel_offset_y, and viewmodel_offset_z"

"viewmodel_offset_x" = "-8.5"
"viewmodel_offset_y" = "-6"
"viewmodel_offset_z" = "9"
These are my settings that I used to center it but when I loaded into another map it off-centered the gun, so I set every offest to zero and that centered it again.