Also, there is a difference between "powder coat" and "hitek" coatings, Powder Coat is (in my view) all encompassing, including the powder coat paints used in automotive and other manufacturing. Hitek is basically the same end result (a bit thinner and smoother result I think), but is a commercial product designed specifically for bullets (could be wrong here), and goes on wet instead of dry like normal powder coat paint.

My powder coating method:

Powder coat I use:
I have been successful with Harbor Freight Red powder coat. I don't know why, but it is known to be the best of the Harbor Freight colors for coating bullets. I would not recommend starting with this however, I would suggest any of the powder coats made by Eastwood. I use their "light ford blue" and it it covers well. https://www.eastwood.com/hotcoat-powder-ford-light-blue.html

I think Powder by the Pound and Smoke's are also brands people use for this.

Procedure:

after casting the bullets, I shake them around in a yogurt or similar plastic container with a little bit of the powder. Plastic containers have static electricity that causes the powder to stick to the bullets. Containers with the Recycling symbol 5 seem to be the best for this. These are the soft white plastic tubs like for yogurt, cool whip, cookie dough, feta cheese and stuff like that.

Once they are covered, I dump them on a piece of mesh to get the excess powder off, then either bake them on the mesh, or on a piece of baking parchment paper. Some people stand them up using forceps or gloved fingers, but I think the slightly prettier bullets that come out are not work the hassle of standing them all up. you can always coat them again if there are some bald spots from bullets sticking together or to the mesh.

I bake them in a old electric toaster oven I got for 5 dollars from the salvation army. The "rule" is 20 minutes at 400 degrees, but I've played around with lower temps for longer and gotten good results.

After they are done, I quench them in water. To test the adhesion, you can smash a coated bullet with a hammer, the coating should not come off and should flex with the smashed bullet.

Then just load as normal.