I already made 100 of these, and they are impossible to pull,..
Nothing is "impossible" to pull, if it were, you couldn't shoot it. Some things are more difficult than others, or require different methods or tools, but it can be done.
As to the couple fired cases and their condition, the reason is, you're shooting them out of a GLock.
I freely admit I don't like Glock pistols, GLock management & some of their history, and I detest the "fanboys" who have "drunk the Kool-Aid". But its not Glock bashing to recognize and discuss their features for what they are.
Glock, like some other firearms makers down through history has made a deliberate choice to do some things others didn't. Their focus is on operational reliability. (not a bad thing) One of the things they did, and do, is make chambers that ammo feeds into with a high degree of reliability.
The down side to this is that it often stresses the brass to just short of the failure point. But as long as it doesn't rupture and works ONCE the designers (and the military) are happy. Like the .303 British the "generous" chamber ensures that the ammo gets in, and works once. After that they don't care. Reloaders like us, care, the gunmaker and its major customers (military & police) don't.
When GLock began making .40s & 10mm, they kept the concepts that worked with their 9mms. This turned out to be on the ragged edge for the .40s and there were a significant number of "Glock Ka-booms" due to the chambers not supporting the brass enough. This is the reason for aftermarket (with more supported chambers) barrels, and Glock themselves slightly redesigning their barrels in the latest Gen models.
The Glock "smile", bulge, belly or what ever you call it is an issue for reloading. Standard dies may not "fix" it. There are "bulge buster" dies that do, but the case is being "worked" a lot, in a place its not meant to be.
Personally, I have my doubts about case life and the wisdom of reusing the very bulged brass. People are doing it, and it seems to be working well enough, but I think its something one needs to watch very closely.
watch things very closely, don't expect a lot of brass life, and be aware that the reloaded bulged case MIGHT fail at any time, even with light loads.
Glock knows this. They always have known this. Glock says don't shoot reloads. Glock voids your warranty if you do. (or they did when they first started out, I don't know if they've changed their minds since..)
I read somewhere ages ago, when Glock was new, that they required the fired brass (9mm) from their test ranges to ONLY be sold as scrap, and not allowed to be resold as fired brass for reloading, and the brass dealers buying their fired cases had to sign a contract stating they would not sell them for reloading, only for scrap brass.
This made sense, if you consider that cases fired from the "relieved" Glock chambers could not be counted on to survive another firing cycle. They often would, but in our CYA world, they couldn't be counted on to do it every time.
If you are wanting the longest practical brass life (and what reloader doesn't?) Glocks, even the improved chambers in the new ones, simply aren't the best way to go.
Balance that against the good features of the pistol, what it does well, and what you like, and decide if you can live with the bad in order to get the good. Your call, there's no free lunch.
Lots of people get aftermarket barrels with more fully supported chambers and are very happy with the results, getting the "good" GLock features and minimizing the "less good" things.
This means spending some more $$, of course, but balance that against the cost of a possible "ka-boom" and Glock's historical policy of not repairing damage "caused by reloads" as covered warranty work.
Keep an eye on your brass and remember that they can fail even with light loads.
Good Luck!