Because of the bulk of powder for most shot shell loads, doubling the powder load and continuing on with the loading process, is not likely to happen if all the components have been used and none have been changed or substituted. With a double charge it would be HARD to get a proper crimp using the components that you had been using because of the volume inside the shell being taken up by the proper components. this is particularly true for the 12 ga shells. Not so sure that it would be as noticible with the smaller guages.
I'll have to agree with what's stated above. It's very hard to double chage a hull and still get everything to crimp up like it is supposed to. The only exception to this is if you're loading some of the newer dense powders like Tightgroup.
If you ever have a bad feeling about a shell(s) then tear it down and reclaim what you can.
I tried to load 2x and 3x shells.. here is what i got..
the components other than a spent primer on the 2&3 charged shells are
Late model 2nd fired aa hull, pink 7/8 dr wad, 7/8 oz shot (homemade) and 700x powder
the red shell had 14.2 grains of powder
2nd silver has 28.4 grains
3rd has 42.6 grains of powder
the double charge is a really nice crimp with 1 piece of shot showing in the center, the triple charge is a usable crimp with 3 pieces of shot showing, still very usable and to the un knowing or un attentive eye would drop right into the shell box with not much thought other than i better shoot it first before the shot starts falling out.. so in my case with the 700x 3 charges and no really big standout difference, it can happen..
Thanks for the replies. I have 6-8 boxes that I loaded on a progressive many years ago. I only remember that I was having trouble with the reloader for a bit and wondered afterward if I might have accidentally double charged some hulls while I was working on it. There are a couple with questionable crimps so I won't shoot those. I guess my question is has anyone ever fired a double powder load and how dangerous might it be through a gun that is mechanically sound?
You might take the time to cut open and weigh a shell with the right recipe. Then weigh the suspected shells (without cutting open) one at a time and record the weights. Any shell that is more than 6 or 7 grains heavy should be suspect and for safetys sake not fired. Cut it/them open and salvage the components. It's better to err on the side of caution. Good luck.
I've gotten a double charge three times and shot them in my XT, no damage to the gun but I sure knew about it. There was no way to tell by looking at the shell. MY loader was giving me some problems at the time and I took the suspected shells apart and did find a couple more. I measured the powder and it was exactly a double charge, I considered it dangeous and bought another loader and have had no problem since.
WHY SHOOT THEM AT ALL?
Shooting them in the back yard is more of a waste than just salvaging the components, and includes the possibility of injuring yourself and/or damaging your gun. It sounds like you just have to shoot them for some reason...??
People do the dumbest things. I knew a guy who somehow double charged a shell with Red Dot on a Mec. When the shot spilled out of the hull he just raked off enough shot to get a crimp and went on. When he fired that shell at the club it was LOUD. But no apparent damage to his 870 Trap. The light shot charge may have saved the day. If anything looks wrong, take the time to figure it out.
If there is an obstruction in the barrel, such as getting a 28 guage shell mixed in with 12 gauge, that is much more dangerous than a shell with an overload of powder, all the guns I have known that blow up were caused be that sort of thing.
I have fired two double charged rounds (34.4 gr 700 X) before I figured out what was going on in my old 1100. People will tell you it can't be done. but it can happen and sometimes the crimps are not all that bad. I assume the wad column crushes to yield the space. my 1100 survived the ordeal both times, but the noise and recoil were tremendous.
Sorry but the weight thing wont work either, just weigh some hulls and see what deviation you get. Then figure in a 1-3 pellet difference in shot weight! It all adds up to a wide range of weights and depending on the original powder charge weight you would have too broad a window to accurately detect the bad shells.
Been there done that ended up cutting open 150 shells and found two more doubles that we had went thru and weighed and thought we had any that could be bad!
Ran one double thru an 1100 and thought WTF was that............Then a few weeks later it happened again. Time to cut them open risk your life and limb over some huls and wads, not me!!!