Well... they worked!
I started low and worked up to about .3gr more than the book said I should just to see how close I was. I checked the primer and empty case after each shot and looked them over very closely before moving on. I did notice just the slightest bulge in the brass where it was unsupported in the chamber. I don't think it's much, but it's something I'm going to keep an eye one while reloading in the 10mm. Another thing is that the rim of the brass was getting a stronger burr on it from the extractor as the pressure went up, but some of that will smooth out in the tumbler so I'm not too worried. Another thing I noticed with the berry's plated bullets specifically is that as the powder went up the bullets didn't make as clean of a perfectly cut hole in the paper target anymore. The shots were still right where I wanted them, but they were more torn than a perfectly punched hole.
When I tested the plated rounds, I did so side by side against Hornady XTP/HP bullets; grain weight by grain weight and neither of them showed pierced or blown primers. I specifically used Winchester primers in these 10mm reloads because I know they're softer and will show pressure signs sooner.
My barrel did get a little bit dirtier than I would have liked, and I think a large part of that is due to the berry's plated bullets. All things considered, the ammo was safe to fire and nothing went horribly wrong. I only fired about 40 rounds between the two different bullets and powder weights but I think I saw what I needed to see.
My conclusion: While the berry's bullets are safe to use at standard JHP powder levels in my gun, I don't think they're something I'd buy again. While I did save money buying them, there is some piece of mind that’s worth a little bit more money to me. On a good note, I have just shy of 1000 of these Berry’s bullets that I intend to run through and dump down range asap so I can move onto the next bullet that will be my new reloading play thing.
I can’t say enough about how much I appreciate the help guys! This forum is a great resource and I don’t know what I’d do without it.