I have the 3M Accuspray with both the 1.8 and 1.4 tips. The 1.8 tip will lay primer fine with very little over spray. I received it while in tech school and both of my instructors who have been spraying since the 70's couldn't believe how little the over spray was. Each went and purchased one for their home shop. I played with the 1.4 tip and it can lay a solid base, but don't expect it to do anything with pearls or metallic. It just can't atomize like a SATA or IWATA.
My guns that I use are the purple Northern Tool gun that Barry recommends for epoxy, it sprays it nicely. I then use the Accuspray for normal primer. Sata 4000 BRP for base and clear. Hope that helps.