you may want to look at the new 3m modular gun
https://www.amazon.com/dp/B01497MZB6...748420_TE_item
watch the videos at the bottom of the link page
We just got one and it works off 13 cfm at 20 psi. We got it because we don't paint we only prime and not often, The gun would get blocked and unusable between jobs if it wasn't cleaned properly.. This 3m gun solved that problem.
Everything is replaceable except the spray handle. you mix in the cup, the lid has a filter in ot so you just pop it on the gun and spray. if you don't want to clean it just toss the parts away and start over on the next job or color