I was shooting some old Federal Hydro-Shock ammunition in my Glock 23 (40 cal) today and on the third round the extractor ripped the case head clean off the cartridge, leaving the hollow cartridge cylinder stuck inside the barrel. The ammunition was not reloaded but was "new," although it was purchased at least 30 years ago. Is ammunition left in storage for extended periods more prone to case head separation? Should I dispose of the ammo without firing it? What do you think caused the problem? The Glock is new, with probably 100 rounds or less fired through it and has not shown any other problems of any sort. Any advice or commentary would be most appreciated. Thanks!
This is 45 year old gunpowder.
ten year old
thirty one year old gunpowder
30 year ish, I forgot the exact year I pulled the bullet
probably around 20 years old
Millions have seen these in in print magazines and never understood the implications:
that gunpowder deteriorates, and its lifetime in unpredictable.
Nitrocellulose is the primary component of gunpowder. All of the nitrites of cellulose are unstable. Any one remember silver nitride film stock? Used to burn Movie Theaters down and still today, very scary for the film industry in storing old films.
This is a very long, but very interesting read:
The Use of Cellulose Nitrate in Art Conservation
Dr. Charles Selwitz Getty Museum
https://www.getty.edu/conservation/publications_resources/pdf_publications/pdf/nitrate.pdf
a taste:
Cellulose nitrate is the polynitrate ester of the natural polysaccharide, cellulose, and for a polymer averaging 2.3 nitrate groups per glucose unit has the structure shown in Figure 1. The molecular weight for most commercial products ranges between 20,000 and 250,000. This semisynthetic polymer was first produced more than 150 years ago and is the most important and only commercially available inorganic ester of cellulose. Due to its unique physical properties and low cost it has been an important factor in many advances in the industrial arts and sciences over the years. Cellulose nitrate was initially used in the manufacture of military explosives where it came to be known as "gun cotton," the first major development in explosives since the introduction of black powder. When it was discovered that cellulose nitrate could be stabilized with camphor (in the ratio of 4:1), the resultant product, celluloid, inaugurated the advent of engineering plastics
In the years following World War I, cellulose nitrate lacquers and coatings were developed. While these have since been superseded by better materials, the largest industrial use today of cellulose nitrate (now also referred to as nitrocellulose) continues to be in its capacity as a lacquer, although substantial quantities are still used in explosives and propellants, printing inks, and plastics. Currently, the total commercial production of cellulose nitrate in the United States approaches 100 million pounds a year
n terms of stability, however, cellulose nitrate is a very suspect material. It does not have the resistance to degradation possessed by most other polymers used in conservation. Only when stability is defined as "the maintenance of solubility and reversibility" can cellulose nitrate, which degrades, but generally does not crosslink, be said to have stability
Chapter 3 Causes of Instability
Most of the literature on cellulose nitrate instability describes three primary modes of decomposition: hydrolytic, thermal, and photochemical. These modes are examined in this paper with concern for rates and mechanisms most likely to prevail under ambient conditions. Recent research can be interpreted to show that these three modes can be redefined into more fundamental mechanisms for primary decomposition, a finding that may provide additional insight into the properties of the polymer as well as the optimum conditions for its use. Primary decomposition processes slowly lead to breakdown products. If these are not swept away they can lead, catalytically, to a faster and more extensive degradation than that caused by the primary processes that engender them. Conclusions on the chemistry of decomposition caused by these breakdown products, i.e., secondary processes, are integrated with our analyses of the primary modes in the next section-a discussion on the overall stability of cellulose nitrate at ambient conditions.
The thing is, as gunpowder deteriorates, it gives off NOx particles. One of which is nitrogen dioxide, which is a horrible oxidizer. If there are water molecules around (call them humidity) the NO2 will combine and form nitric acid gas. Both of these attack brass and weaken it. The fact you are getting case head separations with 30 year old ammunition, I am going to claim that you are seeing the results of gunpowder deterioration on your cases.
I have seen it boat loads of times with my ammunition. I did not know that I should not load ammunition and leave it around. I was taught, as were most of the shooting community that gunpowder is immortal, or if it does fail, it fails benignly, a big nothing burger. Just shows the in print writers really don't have much of a knowledge base. If they were experts, they would know this.
My advice, stop shooting that ammunition. Old gunpowder also has burn rate instability problems and there are lots of threads where old ammunition has blown up guns. It is not worth blowing a $600 Glock to use up old damn ammunition.
If you can pull the bullets, dump the powder, dump the cases, and save the bullets. With case head separations, the cases are toast. Sorry.
