I have broken NUMEROUS Lee decapping pins. The little Unbreakable set that comes with the brass holder, usually black in color is the worst. They have no collet to tighten. I have never had one go more than 5 or 6 cases without failure.
The universal decapping die set is way better is way better, but I have broken 2 of these. The strongest one seems to be the one in the sizing die, I used it to finish a load of 1000 military .223 brass, after breaking 2 unbreakable ones, and the one in my universal decapper.
No problems with pistol brass...trust me, with military brass, at least .223 they are fairly easy to break, bend whatever. I buy them several at the time. Like others have said, its a balancing act on how tight to tighten it. Too loose, and you will have to stop several times to loosen, push back down, re tighten. Too tight, it will break or bend, then you have to remove, replace, retighten.
Russellc