My brother bought 500 or 1000 rounds of that Freedom ammo and it's not loaded too hot. We have shot it in his no dash 629 and also my 629-3 Classic and neither of them had any leading issues and it was a lot wimpier than my handloads. And I have used the Xtreme bullets in the past in several calibers and never had any problems with undersized bullets in any of them. Now, you can push them hard enough to peel off plating, but unless they let out a bad batch of 44 ammo that wouldn't be happening with Freedom's loads. I'm also leaning towards a rough bore from the meloniting process you had put on it, especially after seeing the copper fouling from the jacketed bullets.

I think you need to run a bunch of jacketed stuff through your barrel and see if that helps smooth things out.

If you reload, for reasonably priced 44 jacketed bullets, you might try some Zero 240 grain JSP bullets. I haven't shot their 44 bullets, but I've shot a bunch of their 357 bullets and they are as good as the big names. I think them offering 44 bullets is new too, as I never saw them on the Rose site I linked to until now.