I don't buy bullets but I do cast my own, have since 1985. I use the traditional lyman 450 luber/sizer along with the tumble lube alox & 45/45/10. Started powder coating my own cast bullets in 2014.
The alox, 45/45/10 & pc (powder coat) use a lee push thru sizer (if needed).
The pc coating is a lot cleaner to use/shoot and doesn't gum up the reloading dies like the 45/45/10, alox & traditional lubes.
You can use softer alloys when casting your own bullets if you pc them. I've ran full house 357/44mags/9mm's with +/- 9bhn alloy with excellent results/accuracy.
PC'd bullets tend to have higher velocities than their traditional lubed or plated counterparts. Typical increase in velocity is 2% for traditional cast/lubed/sized and more for pc vs plated.
It's easier to find accurate loads with the soft pc'd bullets compared to their traditional lubed/sized counterparts & plated bullets.
At the end of the day the pd's bullets run cleaner, are not pressure dependent for the alloy of the bullet & are faster for the same load. A win/win/win that makes for quality range time.
500+ round range session using 125gr pc'd bullets/1100fps+ 9mm loads.
It took 1 wet patch (hoppe's #9) and 1 dry patch to clean the bbl. No brushing needed/required.
200 round range session using 158gr pc'd bullets/15,000+psi 38spl load. Didn't bother to clean anything.
While harbor freight pc will work it pays to spend the extra coin ($$$) and get quality power. Top of the line powder is finer, is easier to get to stick and the coats are flatter/evener.