More Coating Tests. Once again I'm sticking with the same load even though it is not an optimized load, because I'm trying to test the coatings, not the load.
All of today's loads used:
-- plain base or bevel base spitzer
-- 62 grains in wheelweight or 58 grains in lino
-- 24 gr. IMR 4350
-- CCI #41 primer
-- seated right at the jam point
-- sized 0.246" after coating
-- nose sized so that front band was 0.242" on plain base or 0.2415" on bevel base (same setting on nose die).
-- 10 shot groups at 100 yards, but some groups had only 9 shots because there were several dud primers today.
First up, VHT rattle can epoxy plus HVR lube on the plain base bullet. You have to admit it's pretty.
This wheelweight bullet was oven treated at 475F before coating.
-- 2149 fps
-- 1.50% velocity standard deviation
-- mean radius = 0.81"
Next, a lino plain base, hi-tek coating, plus HVR lube.
-- 2185 fps
-- 1.70% velocity standard deviation
-- mean radius = 1.00"
Next, a lino bevel base, hi-tek coating, without lube.
-- 2181 fps
-- 1.27% velocity standard deviation
-- mean radius = 1.07"
Next, air-cooled wheelweight plain base, hi-tek coating, plus HVR lube
-- 2101 fps
-- 1.63% velocity standard deviation
-- mean radius = 0.95"
Today's target. No bragging size groups, but no wild groups, either. The accuracy differences between coatings were too small to be considered significant.
Observations, Conclusions, and Questions:
-- VHT rattle can epoxy seems to be a satisfactory coating, at least at this velocity.
-- Hi-Tek seems to be a satisfactory coating, at least at this velocity.
-- Hi-Tek seems to shoot equally well with or without lube
-- when both are coated with Hi-Tek, air-cooled WW seemed to be just as accurate as lino (at this velocity). I was surprised.
-- none of today's loads leaded the barrel. No leading visible to the naked eye, and no lead specs on a tight fitting patch.
-- the only bad thing about the coated air-cooled bullets was that velocity was 48 fps slower.
-- in general, most of the coatings improve accuracy at this velocity compared to an uncoated bullet. Bear in mind that the uncoated bullet sometimes struggled to stay on the target with this powder charge.
Things to Try Next Time:
-- there's a couple more coatings I want to try
-- continue comparing lube vs. no lube with various coatings
-- continue comparing air-cooled vs. heat treated with various coatings
-- more water tank autopsies when the weather permits
-- once I settle on a pet coating combo, I'll try ramping up the velocity.