First up, air cooled WW with polycrylic shake & dry, but no lube.
-- 24 gr. IMR4350
-- 62 gr. plain base spitzer
-- 0.246" x 0.2415" diameter
-- seated right at the jam point, 2.262" COL
-- 2089 fps
-- 1.81% velocity standard deviation
-- 0.79" mean radius
-- no detectable leading, but a tight fitting patch showed some shiny gunk -- I'm guessing it was polycrylic fouling?

Next, oven treated WW with polycrylic shake & dry, but no lube.
-- seated right at the jam point, 2.273" COL
-- 2185 fps
-- 1.43% velocity standard deviation
-- 1.86" mean radius
-- no detectable leading, but a tight fitting patch showed some shiny gunk -- I'm guessing it was polycrylic fouling?

Notice that with both alloys, the second group was worse than the first group. I suspect accuracy was deteriorating as more shots were fouled due to fouling. Not lead fouling, because there wasn't any, but due to the polycrylic itself fouling.
Anyway, to my surprise, the air-cooled bullet coated bullet was more accurate than the hard coated bullet. I have no explanation. These coated bullets are forcing me to rethink everything I thought I knew about cast bullets.


Next up, air cooled WW with no coating, just ordinary HVR lube. This was a control to compare to the coated air-cooled bullet.
-- seated right at the jam point, 2.262" COL
-- 2112 fps
-- 1.74% velocity standard deviation
-- 2.40" mean radius
-- there was a tiny bit of lead specs on a tight fitting patch at the end of this string. Not at all severe, but it was there

Definitely inferior to the polycrylic coated air-cooled bullet.

Conclusions, Observations, and Questions:
-- air-cooled WW outshot hardened WW, using polycrylic and no lube.
-- polycrylic coated air-cooled outshot non-coated air cooled.
-- polycrylic may cause polycrylic fouling if there is no lube.
-- polycrylic may be an "OK" coating, but it may benefit from lube.
-- hard bullets are about 80 - 100 fps faster than soft bullets, probably because the hard bullet has more engraving resistance which increases the chamber pressure
-- hard bullets have less velocity variation than soft bullets, again probably due to increased engraving resistance which helps the powder burn.
-- I'm still favoring polycrylic or urethane shake & dry as my favorite coating, even though the polycrylic seems to foul if used without lube. Rustoleum enamel is out because it did not stick well. Rattle can epoxy paint shot well enough but the adhesion was marginal. Rattle can urethane shot OK but it costs more than a shake & dry coating. Hi-Tek shot well but is not compatible with heat treating.
Things To Try Next Time:
-- air-cooled polycrylic with HVR lube
-- air-cooled polycrylic with a waxy tumble lube, like Rooster Jacket or Johnson's Wax
-- otherwise I am out of coatings to try and ready to move on to higher velocities. How fast can I push coated plain base bullets before they go wild ?
-- is there any benefit to coating gas check bullets at high velocities ?
-- long term, I'll probably revisit powder coating if and when I get a spray gun.
-- long term, I would like to try a shake & dry with 2 part epoxy paint, if I can find some that cures OK at room temperature.