Ditto for me ,copper plated bullets in a 38 Super1911.
Its dead soft pure copper. Thats way different than the much harder guilding metal jacket
In my case,the copper buildup effectively increased the length of the case over the case mouth, so there was interference with my chamber headspace.
Don't feel like the Lone Ranger!! The University of Murphy's Law gives a well rounded education...eventually!
As the Quality Dude J Edwards Deming taught (and I am sure you are aware)
Quality assurance in setting up the process is a good thing. Inspect to make sure you start out making good ones.
Ideally,once you find that setup,you have means to repeat it.
Feed in 100% good components, eliminate variation from the process,and you get 100% good ammo.
Do use in process inspection to monitor any variation.
Inspecting quality back in,after the fact...inspecting,sorting,rework...
present an excellent opportunity to improve the process! (A little more bell)
And now you have progressed!!