I am quite curious about brass case failure and its consequences.
I reload my 357Mag hot (16.2gr of h110 with HSP 158gr).
One of my favorite loads, I only use once fired brass for h110 loads (most of my loads are moderate ammounts of bullseye under a 158gr plated). I shoot this mostly in a lever rifle, but occasionally in a revolver. This is also one of the few loads that I will trim brass for. I have some 357 brass that has been loaded lightly about a dozen times, and is still within length specs, but heavy magnum loads can and do streach it, and have found it normally takes about 2 or 3 hot loads to streach it out of spec to where problems could happen. Most people don't trim straight wall pistol brass, and don't have any problems, but to me 15minutes, and a $5 trimmer pilot are cheap insurance.
happens every so often, worst case with a bad split is that the brass will get stuck, and has to be tapped out from the front of the cylinder with a brass roll pin punch, I have never seen any damage resulting.
Separation of the head and case
Very rare, this happens mostly with new brass, and is often a defect, not from wear. It can blow up a rifle where the breech is locked in place, I would think most of the blast would be stopped by the recoil shield in a revolver, it could light off other cartridges in adjacent cylinders, but if not, there probably wouldn't be much if any damage, possibly some powderburns on the hand.
if meant as a severe split lengthwise, basically the same tapping out with a brass punch I discussed earlier may be needed, still no damage likely.
now the failures not discussed:
Squib load:
a problem with the loading process or storage, mostly from not paying attention, and forgetting the powder charge, or can be with a slow powder (like blue dot/h110) and a weak primer, or even oil getting to the powder (gun heavily lubed, and stored loaded), basically the primer fires, the powder either doesn't light, isn't there, or partially lights, lodging the bullet in the bore. No big deal if caught, the bullet can be hammered out with a brass rod, if not caugt, and the next cartridge fires, the barell can be blown off, cylinder blown out, or in the case of a guy with a redhawk a couple years ago at my range, a puzzled look as two holes were put in his target, and a slight bulge was seen in the barrel.
Punctured primer:
very rare-firing pin puts a hole in the primer, either by having a chipped or too long firing pin, soft primers, or pistol primers in a case designed for rifle primers (454casull), this can blow a frame mounted firing pin out of the gun, bounce it off of the hammer, and send it flying, more than likely, this won't happen. Most likely is a pit would be burned into the recoil shield face.
primer blow out:
wouldn't have belived it if I hadn't seen it. Basically a delayed ignition in a revolver with an excessive cyl to recoil shiled spec, or thin rims on the brass, could possibly happen with a really loose primer pocket. Where the firing pin pushes the cartridge forward before the primer lights, primer pushes back out of the case, and when the main charge goes off, the unsupported primer blows apart, and basically turns the flash hole into a blow torch nozzle, similar to a punctured primer. The guy that this happened to burned his hand, and had a big black circle burned around his firing pin, bullet hit about a foot low at 25yds, and a peice of the primer bounced off of my safety glasses, I was in the next lane over. (I never have shot without good eye protection after that)
Basically you are most likely to encounter a split case, no big deal, tap it out, most other failures are kind of like winning a bad lottery, very unlikely to happen. Most are due to wrong components/data used, a damaged or worn gun, bad brass or carelesness. Even factory ammo can and does have defects, so pay attention, be safe, keep a close eye on your brass, and happy shooting
