As far as bolt failures are concerned, I recall Hatcher doing a bit of "research" along these lines. (His research typically ended in something blowing up but it makes for fascinating reading.)
Here's my point of view as an armorer:
Most firearms, today and yesterday, are massively overbuilt. There's a tremendous safety margin engineered into them from the beginning. If you doublecharge a rifle cartridge you'll usually blow the sucker up but there's only so much that you can realistically engineer around. I've seen some firearms (usually pistols) that will tolerate a double charge...not a good idea, but that's how overbuilt they are.
I've seen a few guns go boom - my M48, my room mate's FAL, an M16, and an M14. It's worth noting that in none of these cases was the shooter seriously injured. I picked up a powder tattoo on my forehead from my little accident. The room mate caught a few bits of brass in the face. The M16 shooter wound up with a gas cut and some aluminum cuts, the M14 gunner was fine. In all cases the shooters were wearing safety glasses. In all cases, I believe that some eye damage would've resulted without it. (My own safety glasses looked as if they'd been sandblasted and had to be thrown away afterwards.)
None of the weapons were fit for firing afterwards, of course. The FAL survived and the M48 probably will after some extensive reworking. The M14 and M16 were goners.
The Mauser's safety lug gets undue attention. There are some other bolt guns that deleted it simply because (as was mentioned) it's really not necessary; if you have enough bolt thrust to break the two primary lugs, that third lug ain't gonna do much. The root of the bolt handle itself probably provides more support. The normal mode of failure (as I understand it) is that the lug taking the lion's share of the thrust shears and the bolt cocks to the side, essentially jamming itself in place.
Take a look at the locking lugs of modern military firearms...and even some not-so-modern firearms. Forget the M16 (which has a bunch of little locking lugs) and look at the much-touted M14/M1 Garand. There are only two lugs, they're not too large, and they lock into the receiver instead of the barrel. From a firearms designer's standpoint this is a bad thing for a variety of reasons that are beyond the scope of this post, but it works and works well. The much-praised H&K roller locking system uses considerably less surface area for locking but not too many folks complain about that. (If you get the chance, look at it sometime. It's scary.) A design that seems like a bad idea on paper is not always bad in reality, and vice versa.
The Beretta slide comparison is a bad one. This is truly a case where a couple of failures, a long time ago, created a true mythology. There's a lot to this story: Beretta said that the ammunition was overpowered (true), and the government said that the steel was substandard. (Also true.) The ammunition was downloaded a bit, the steel was upgraded, the design was modified and there hasn't been a problem ever since. (Not that problem, anyway. There are others.) I haven't heard of a slide seperation since I've been on active duty. (1996.) On second thought, it may be a good comparison...a couple of hiccups early in the weapon's lifetime and the reputation is earned.
No safety lug? Not a big deal to me. The M14 doesn't have one. The AK-47 doesn't have one. The M2 doesn't have one. The M242 doesn't have one. (What a set of locking lugs that thing has, though...) In short, were it necessary, people would still be making them. The militaries of the world realize that it only takes a couple of failures to cause a lack of faith in the weapon system and they take great pains to avoid this.
My guess is that there were a few failures - probably from improperly loaded ammunition - and it started from there.
HD - good idea for a vid. No promises, but if the opportunity presents itself, I'll generate a few fireballs for the record.
The thing's even got a decocker, kind of.
