Burt,
You should be able to paint anything imaginable in modeling with your current airbrush.
Don't let the hype of needle diameter steer you in a direction that you think may help you paint better as it's a fantasy. Needle taper is the determining factor for line width, not diameter!
Now, with that in mind let me add that some of the finer tapered needles may or may not work well for modeling paints. People think that the higher-end the airbrush, the finer the line, but that is simply not true. The diameter of needles and the faster taper of them apply to certain mediums only, and that means using paints that we do not use such as watercolors and urethanes.
With a Badger 100LG, Badger Renegade, Iwata HP-CS, or any other high-quality airbrush, with practice, you can paint anything you want to on models regardless of needle diameter.....period!
Now if you are having problems painting with the needle and tip size you have because of clogging and so forth, then the needle size could be too small but I am not sure as I don't use that particular airbrush. I know many times that modelers will have problems with a #1 needle and tip in Badger and Paasche airbrushes and switching to a #3 is better all around.
Is that possibly what you are experiencing?
“Wisdom is the right use of knowledge. To know is not
to be wise. Many men know a great deal, and are all the greater fools
for it. There is no fool so great a fool as a knowing fool. But to know
how to use knowledge is to have wisdom. " Charles Spurgeon