Melt them all down and start over. One correct coat should do it everytime.
Powder coat is ..............................finicky?
So after you cast them, you'll want to do an alcohol or similar chemical wash to get rid of any garbage on the surface. Anything like skin oil can really hinder adhesion. Get some of those nitrile gloves.
If your shaking them- You'll want airsoft pellets. I think the black ones are recommended. You'll need a good static charge to get the stuff to stick. You also want to do it in an area that has little humidity, because that can cause it to clump, which looks like what happened there. It really takes a good 10 mins of shaking to get them to cover right.
If your using the gun- Same humidity rule applies. I had soldered some .035 mig wire to the end of the tip, maybe 8 lengths, and fanned it out a little so made a more even charge across the powder. Do it on a baking sheet with tinfoil and get a decent ground. Its not like painting with an h.v.l.p. gun. You'll want to run it in 4 directions. North/ South/ East / West to get a good coat.
When you bake them- Get a decent small oven. Nothing huge or fancy, but you want it to hold that temp fairly well. I think I was at 425 on the dial. Pre-heat it, get everything laid out, then pop them in rikki-tik. Takes about 15 mins or so to bake. You'll see the powder start to gloss over. Once they're glossed, its maybe another 5-10 mins depending on batch size. The coating should be smooth.
Certain powder colors also gloss over better than others. I had decent results with h.f. red, but the go-to stuff is (or was) was Eastwood Blue. It looked the old ford mustang blue.
Powder by the Pound (haven't done it in years, not sure if they're around or not) was another recommended brand.
If you haven't, check out this forum-
Coatings and Alternatives
Ton of info, and can give you the exact process.
I'm not shitting on your results.
When I first tried it, I had to re-melt at least half a dozen times. It is a process and steep learning curve.
This is why a lot of people switched over to Hi-tek.
Powder coat goes on dry and you have to liquefy it through heat to get it to fill and bond. And the stuff can get everywhere. Small batches are the key, like 50 or so at a time.
Hi-tek goes on as a liquid and fills better and you use heat to harden and cure.