If such a cartridge as described above sat long enough, it would eventually lose enough nitrocellulose that even the greater burn rate would not cause too much pressure, and then the ammo could be fired, but like any charge of fast pistol powder in a rifle, it has little progressivity and produces poor velocities, so it simply seems weak
Unclenick: I don't know about this. The long enough is more of the kicker, 50 years, 100 years, 100,000 years? I would think around the first millennium gunpowder would have very little energy left, even in a dust form. But, based on pictures I have seen, the stuff breaks down to a dust, and that has a huge surface area. There are some great documentaries on cable, I watched on the sinking of the Lusitania. There was a big bang after the torpedo explosion and the program tried to explain it. One of the theories was coal dust. It is surprising the amount of energy there is in coal dust. It was also surprising how much energy was in aluminum dust. Anyway, if gunpowder breaks down so that there is dust in the case, I think that would spike the pressure curve. I don't know when gunpowder breaks down to the level that there is not enough energy in it to blow up something.
On the other hand, if it has been sitting in your deep freeze, it won't expire until long after you and maybe the next several generations do.
Powder life is very unpredictable, there are more and more reports of 20 year old Vihtavuori powder going bad. This guy had late 1990's Vihtavuori cause inside the case corrosion and gave high pressure indications. He said it had been stored inside at room temperature since he bought the powder.
9.3x62 and VV-N150.. powder deteriorating?
http://forums.accuratereloading.com/eve/forums/a/tpc/f/2511043/m/3311048312
I used your N140 picture and post. Thanks.
T.O'Heir assumes, that because he fired 1944 303 ammunition in the 80's, that that means all ammunition must be good for 44 years. What T. O'Heir and others who use his anecdote as proof of the immortality of gunpowder don't realize that this is a case of selection bias. T. O'Heir is unaware of Ammunition Technicians, behind the scenes, inspecting, testing stockpiles of ammunition. Ammunition that has deteriorated is removed from inventory and demilled. The US military demills on the order of 500,000 tons of ammunition per year. Not all of it is small arms, but from what I read, the majority of the weight is small arms ammunition. Sometimes cases fall off the truck and the stuff gets sold to Americans who think it is as good as new.
This is an example of what is going on behind the scenes, I got these charts from 1969 and 1970 convention presentations.
1969 Ammunition Surveillance
1970 Ammunition Surveillance
So, a shooter on the line could be issued 30 year old, or 40 year old ammunition, assume all ammunition must therefore last 30 to 40 years, and yet, he does not see, nor is he aware, and infact, it is beyond his comprehension that there are technicians going through ammunition stockpiles and weeding out ammunition which could be younger than what he was issued.
I am going to say, the lifetime of gunpowder is very unpredictable. When ammunition gets around 20 years old, you should have shot it up 10 years ago. With older ammunition, pay attention to pressure indications and case splits. If the ammunition has a lot of case splits, the powder has deteriorated the case and I would pull the bullets, dump the powder and cases. If the ammunition provides high pressure signs, I would pull the bullets, inspect the cases, and dump the powder.
