Not a huge fan of Vallejo paint line due to their rubbery/vinyl feel when dry.
However…. Model Color is not made for airbrush use. You need to get Model Air. Some folks say Model Color can be airbrushed but I've had zero success airbrushing Model Color line.
Red is a hard color to airbrush (yellow even harder). Best way to achieve the red, spray in several light coats until you find the desired shade you're looking for.
Vallejo doesn't have a great selection of different shades of red
compared to other paint brands.