I still want the Apex when I can get one, just to see for myself if they are onto something or not.
In the meantime I have a setup that works much better than the original extractor setup that came with my 2012 tested Glock 19 Gen 4. My gun has all the latest parts. Even with the original, very weak, extractor setup it did not jam in the hundred or so rounds I put through it before starting my experiments. I did get a lot of Brass to the head and otherwise weak and erratic ejection.
My solution has not eliminated erratic ejection completely, but I haven't had any hit me lately, and they are more or less going in the same direction.
Here's what I did. First I ordered and installed the Lone Wolf Distributers (LWD) extractor, extractor spring, and spring loaded bearing (SLB). That helped, but I was not there yet.
Next I started playing with the SLB, making my own on the lathe. I have some nails that, by coincidence, are exactly the right diameter. My goal in doing this was twofold. First, by making the head of the SLB a bit longer, I could tension the spring a bit more. Second, I noticed that the ejector plunger tip at the rear was beating up the tip of the plastic SLB even after a few rounds.
Now, the overall length of the SLB is important. As the extractor moves out, compressing the extractor spring, the pointed tip of the extractor plunger hits the SLB, limiting the travel of the extractor.
The LWD SLB is .480 in length. The Glock SLB is a bit longer, but cupped at the end to mate with the plunger tip. I have no way to measure the exact effective length. Problem with the Glock setup is that the SLB is stepped down, and the SLB's are not exactly straight. So the plunger tip was beating up the edge of the cupped end rather than mating as it was designed to do.
My solution, arrived at after some experimentation, is a steel SLB, just short enough in total length to allow the extractor to chamber a round, and not stepped, so that the plunger tip hits it squarely in the middle. The maximum length I can make my SLB is .477. Note the end of mine is slightly rounded, just enough to make sure it will not hang up on the spring. Note also the slightly longer "head", causing just a bit more spring compression. Shown with LWD SLB for comparison.
The second photo shows the new assembly, with a White Sound Defense 20% extra power extractor spring, my last improvement. Note the distance between the tip (which you can't actually see) of the plunger on the left and the SLB on the right. After pressing this assembly into the slide, pre-compressing the spring, there is just enough room for the plunger to move back sufficiently to allow the extractor to move enough to chamber a round.
This setup is the best I can do at the moment, I think. The ejection is still not as good as my M&P or my Kahr or my CZ85 Combat. But I'm not getting hit, and I can find all my brass.
I am sure some will say: "Why go to all that trouble if the gun wasn't jamming in the first place?". Answer: to me it is no bother. It is play. And it is how I learn things about how things work, or sometimes don't work so well.