Glocks are inherently (and practically) more accurate than most owners or users may ever be able to realize. (Like other quality pistols made by the big name companies.
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Perhaps more owners/users might benefit from more training and developing a good foundation skillset, and from the opportunity to engage in more frequent proper practice. Shooting is a
perishable skill, you know.
I shudder every time I hear or read about someone doing their own "trigger job", especially the "Glock 25-cent trigger job", a "fluff & buff", etc. Not needed. May cause problems.
Many of the smaller steel parts in Glocks have received some type of plating finish. It's varied now and again over the years. I thought I remembered from my last armorer recert class that they've been using a version of Teflon Nickel in recent years.
A couple of my own Glocks produced from different years exhibit a copper plating layer seen under the finish on some of the steel parts (rails, locking block, trigger bar cruciform, firing pin, etc).
Minor flaking usually isn't a functioning issue (although some folks may consider it an annoying cosmetic issue). If it becomes excessive in the firing pin safety plunger channel or the firing pin channel, it might require parts replacement (consult a local Glock armorer or call Glock).
Just some thoughts.