Which paint water based or solvent based?
Solvent based will do better on your guns. Consider painting the sight white first. Put the glow paint on as thick as possible. Before Glow Forum existed, we had a customer that put up a website detailing his bow sight modification. It used coiled fiber painted in glow paint. Thus, the pointed end at the actual sight was very bright. Unfortunately, I have not been able to find the website again.