Ok, This is gonna be a long one...but given " you coulda put yer eye out" is no more a fairy tale in this instance...I think its justified. YMMV.
I'm very sorry to hear that your friend had an unfortunate experience.
The fact that "upon further review" it was the third time it has happened to him is also unfortunate, but not unexpected given your story of how he arrived at the loaded cartridges.
I'm very glad it wasn't the straw that broke the camels back this time- but it might be next time.
The dies, powder, primer, press...all functionally irrelevant except for the short throw issue...but this is something you may encounter on ANY progressive equipment or process where quantity and speed are the #1 goal, not safety.
Unfortunately if it has happened before, unless your friends reloading mindset is readjusted- I do forecast it happening again in the future.
I will assert, however that weighing your final cartridges is not a fruitless endeavor.
Failing to weigh your components beforehand, although time consuming, DOES however make it a fruitless endeavor.
We have had a number of posts now where this comes up. Yes, bullet weight and case weight do vary- that is a given. They can however, if one is so inclined, be grouped into solid grain weight intervals.
Let me give another example, this time using the weights that have been provided:
45ACP (grains):
Group 1
94.6 PMC
94.0 CCI
Group 2
93.8 PMC
93.6 WCC 93
93.3 PMC
93.2 WIN
Group 3
92.9 WCC 99
92.9 SPEER
92.2 PMC
Group 4
91.0 CCI
90.9 FiocchiUSA
Group 5
89.7 CCI
Group 6
88.2 RP
88.1 BLAZER
88.1 CBC
88.0 WIN
Group 7
87.8 S&B
87.5 CCI
87.4 FEDERAL
87.0 BLAZER
Group 8
86.9 WIN
86.4 FEDERAL
86.3 RP
86.0 FiocchiUSA (Lg Primer)
Group 9
84.7 WCC 71
Group 10
82.9 STARLINE
82.5 STARLINE
82.7 WCC 80
Now, as we all know- 185 grain bullets ( just as an example) aren’t all 185.0 grains. Some will be higher, some lower. Yes, even those precision swagged bullets we all pride ourselves upon being perfect vary as well.
Some don’t think that difference matters.
This is more than likely the best instance I can find of where it does.
Sort your bullets by weight too… I sorted 500 of them the other afternoon…it did take time…yes, it did. But in preventing situations like these- I believe it to be time well spent. My bullets in that afternoons endeavor varied by up to 4 grains :banghead:
However, for arguments sake, we’ll say that all of the cartridges we are making today are using bullets that have been screened, and all weigh within the 185.0-185.9 gr weight.
In group 1, your brass weighs nominally 94 grains. Add 185 grains. That gives us 279 grains of components, not including the primer.
I’ve weighed a lot of primers. A lot. Most of them within a lot don’t vary by more than .3 grains. If you loaded 200 of them, and more than 1 of them was .5 grain higher than the rest I would be surprised, but please- do your own research.
In any event, this gives us 278 grains for group 2, 277 for group 3, and so on.
Applying a 4.5 grain charge to group 1 gives us a weight of 283.5 grains, plus a primer weighing 4 grains ( CCI LRP #300) for a total weight of 287.5 grains. 286.5 Grains for group 2, and so on.
Weighing the finished rounds within 1 grain is good enough for my tolerances….might not be good enough for .40 cal or 9mm…your tolerances are as tight as you want them….This method would however GUARANTEE catching a double charge. It would give suspect to ANY CARTRIDGE with more than 1 grain variance.
For those of you who reload in large enough groups to make it worthwhile, you could ( and I do ) simply tare your scales to each respective grain group…making weighing them far less of a time cumbersome task. It’ll zero out, or show you the difference….you then get to apply your own varying dose of reason if that difference is worth setting the round aside.
Now, is all that work really worth it ?
That’s a personal call. Given what can happen ( did this just happen ? ) when you don’t QC your own product, I’d say its time well spent.
Are there other ways to prevent what occurred to your friend in the first place ? Sure. Being attentive, knowing the equipment, not rushing…there’s an exhaustive list.
However, in the very end, if you can’t measure your finished results to some sort of standard- you better hope your process is 100%, 100% of the time.
If you don’t, and don’t have a halo, or a direct connection to some other higher power…you damn well better have a weapon that can handle that 1%, 100% of the time. I don’t know of any (people or weapons) that are 100%- 100% of the time, does anyone else ? (biblical or other religious figures excluded)
Now- it seems like a pretty significant step, this process. I'm fairly sure it would just be " way too much work" for what your friend is accustomed to... goodness knows I hear it from folks who aren't sitting on the couch all bandanged up. However, sulking whilst chewin on the crow pie is a great time to be reflective upon what got you chewing said delicious slice...and its always when I personally have the biggest ears on for ways to prevent it in the future....your mileage with this particular friend may of course, vary.
Weighing the cartridges, good process IMHO.
I don't want your thread to devolve into an argument about which process your friend should choose, or if the weighing cartridges thing works... so I'm gonna post this one and leave it at that without further comment.( some will smile and rave, and say thats impossible given some recent events/threads- but trust me it is ) This thread should be a heads up to anyone who reloads, and why safety is paramount however you arrive at it- and I won't distract from that further.
I know- it supposedly won't work for you guys who load 15,000 rounds a month, I know. That horse has been kicked to death thoroughly on previous dates. This incident doesn't involve that level of loading- however it is fairly indicative of a regular reloading session for most non-competitive folks.
Will it work for your friend or you ? Don't know. In the case of your friend though, if this step doesn't work- I'd find one that does....preferably before the next bench session- and your time to be a real friend and point that out is NOW.
I don't know whether to laugh or cry ... oh my, this was a PREVENTABLE event 
