From my understanding most painters and paint manufacturers recommend a 1.3 or 1.4 tip for shooting base coat or clear coat, which I use. My confusion is that many mini guns, which I’m thinking of purchasing most often come with a 0.8 or 1.0 tip and are advertised for use with base coat or clear coat. What gives? Also, would a smaller tip have any negative effect on the way the metallic’s are dispersed? Any info would be appreciated.

well believe it or not that number 1.0 1.3 1.4 etc don't mean squat....

is is just a number for us to have some sort of reference to.

all spray gun manufactures could very well be different.
meaning SATA 1.3 may measure different than IWATA 1.3

thats creates a problem when you got people on forums testing guns and putting reviews out there good and bad because they use the same tip size on two different guns to test the same paint with different results. you very well may need a different tip size to spray the paint properly between manufactures.

long story short yes thats correct use the smaller tip size on a mini gun

All mini guns spray with a smaller tip.
Those "recommended" tip sizes are for full size guns only.
Mini guns are a whole different thing.

Dave's on the right track. Different guns may have the same fluid tip size but so many other factors also come into play. The angle of the end of the needle can allow more or less paint through the fluid tip, the size and shape of the inside of the fluid tip can do the same. then there are things like the size, number and layout of air holes in the air cap and internal layout of air passages, design of fan control......the list just goes on. Most painters have used two different guns of the same size and found that one is very slow while the other goes on like a hose.

Almost anything can be painted with any size gun, provided allowances are made. Paint may need to be thinned more, air pressures may need to be lowered and techniques changed. I've painted whole bars with an airbrush or with a 0.8mm mini gun. Not easy and very slow, but can be done. Conversely, small jobs can be done with a full sized gun.

The smaller guns do have a place when doing small jobs. Like anything, using the right tool for the job makes it quicker, easier and more efficient.