Ric, suppose you are an accomplished water-color artist who does illustrations for books and the like. One day you meet someone at the art supply store who's raving about acrylic paints, so you decide to buy a color set and try them. You use the camel-hair brushes and all the techniques you know that work with water-colors, but it makes a mess and the paint is clumpy, streaky, doesn't blend well, etc. because you are applying very good but wrong tools and techniques to the medium. That's essentially what you've done here, because adding the coating CHANGES EVERYTHING.
OK, I will go back and look some more.
This stuff is all about dynamics, whether jacketed, paper-patched, coated, or bare/lubricated. Each type requires its own techniques to get good results. Dynamic fit and powder burn rate are changed dramatically when you put a slippery, tough coating on a cast bullet, and this can hurt you or help you depending on what you do at the casting and loading benches. I can tell you to pretty much do the opposite of what you'd do for a CBA match load and it will work better with PC'd cast because PC'd cast doesn't like a jam fit
Yep, 0.005" jam on the tapered front band into the lead.
(often they benefit from jump and wiggle room), doesn't generally like a brittle alloy,
Alloy is about 3.5% antimony and 2.2% tin from my lot of alloy that does BHn 14.
doesn't like exactly matching tapers, doesn't like to be sized much larger than groove dimension, needs consistent and firm neck tension,
Consistent 0.001" interference fit, no crimp.
and accuracy doesn't tolerate position-sensitive powders or ignition variances very well.
This lot of Alliant is not position senitice at 1425 f/s and SD of 15.
This is why I wanted you to (re?)examine some of the threads here that contain successful pc loads and determine what you are doing differently from those, since you have the rifle and made the ammunition for it and know what you did, and none of the rest of us do.
Here's an example:
View attachment 6804
If my chicken scratching doesn't show up well, the basic info is .308 in WCC 08 brass, SA M1A w/22" pencil barrel, suppressed, left group at 75 yards, next five rounds from the magazine are the right group at 100, 37.0 grains of IMR 3031, Lee C312-155 (Ed's grease-groove design), powder coated, gas checked, lubed with LBT soft, sized an actual final of .310", 10.4 bhn 50/50 COWW/purish scrap, air-cooled, aged at least a year, CCI 200 primers, seated to crimp in the crimp groove (which is a lot of jump, IDK how much but probably over 1/8").
I need to stay above 1150 f/s at 200 yards, so light bullets are not in the picture. Even Military Class I need 1 1/4 MOA at 200 yards.
Now, what did you differently? My guess is your coated bullets are cast of linotype, parked tight in the throat, and launched with fast powder like Titegroup. Whatever it is, compare to how you did it to how I did it and let's talk about the differences and why they matter.