That part of the locking block jumps up and rubs into the bottom of the slide during recoil, having some wear there and on the underside of the slide just outside the slide rails is normal.

I can't see it too well from your picture, but it almost looks like it's wearing down to reveal a copper color. Most parts in a Glock are nickel-plated with a copper undercoat, so it's normal to see the copper color, the nickel plating wears away eventually.

Originally Posted by voyager4520

Most parts in a Glock are nickel-plated with a copper undercoat, so it's normal to see the copper color, the nickel plating wears away eventually.

That's news to me, too. I always thought that nickel plating would be more ornamental than anything else. I don't understand why it would be used on internal parts that are almost certainly heat-treated for hardness. What good is a "copper undercoat" for these parts, other than to help nickel adhere? Voyager4520 normally offers pretty good information, so I'm not debating here, just saying it's a surprise to me.

That aside, it would be real helpful to see a more detailed photo. I looked at the locking block and slide of my Gen 3 G34, that has a few thousand rounds through it, and I do see some mild burnishing on the top of the locking block, with no matching wear pattern on the slide. Of course, I clean my guns after every use, so that may explain any difference in wear.

By the way, if anyone who reads this might have a broken locking block (yeah, I know, it would be hard to find) it would be interesting to try to cut the thing open and see what it looks like in cross section.

Chris

The frame rails of the newest Glocks are nickel plated with a copper undercoat, I've seen the same wear on one of my frame rails, one of my trigger bars, connectors, and extractor depressor plunger. Others have seen it on firing pins, firing pin safeties, and locking blocks.


It seems in some cases it's not even wear, but the plating wasn't done correctly and the nickel literally peels off to reveal the copper undercoat.

You know that old saying, "You learn something every day."? Well, this is one of those days.

I did some reading, and I learned that nickel plating is used in applications where there's a need to reduce friction and prevent corrosion, and that this plating is hard enough to provide good wear properties. I'll be darned.

Voyager, thanks for passing that along!

Chris