View Single Post
  #1  
Old 01-29-2015, 08:54 PM
Buffalo Bill Buffalo Bill is offline
 
Join Date: May 2011
Location: Indiana
Posts: 163
Default Danger with Deteriorating Powder

Much of the .30-06 ammo loaded in WWII (about 70 years ago) with stick powder is still quite reliable, IF it has been stored in reasonable environmental conditions. Also, some of the powder from the pull-down ammo is still usable. However, some powder is also showing signs of significant deterioration and should not be used. I have had a couple experiences with deteriorating powder.

The first one described was with once-fired, relatively new, commercial Remington and Winchester brass in 7 X 57 Mauser. The problem was definitely the deteriorated stick powder, not some extremely old, brittle brass.

On July 4, 2003 I fired some 7 x 57 cartridges that I had loaded with BL-32 military surplus stick powder (roughly equivalent to 4895) in 1984 (yes, 19 years before shooting them). I had noticed some time before the loading (or perhaps a few years later) a few "rust" specks in the bulk powder. In 1984 the powder did not have the odor of original solvents or acid, as I recall. Note the picture below and the descriptions of what happened when I fired the ammo.



Case #1 Second round of 5-shot group with Remington brass, first reload, 44 gr. BL-32, 120 gr. Sierra bullet, grouped 0.52" at 50 yards. Case neck "cut" halfway through near shoulder/neck junction. (Looks about like someone had taken a hacksaw to it.) Other four cases look OK. Average velocity was 2826 ft/sec but with 114 ft/sec extreme spread.

Case #2 First round fired with case that showed a very short vertical neck split before firing. After firing the vertical split is much longer and a horizontal split is starting at the shoulder/neck junction (This also happened to be where the base of the bullet was.) Winchester brass, first reload, 42 gr. BL-32, 130 gr. Speer PSP.

Case #3 Second round fired with same load. Case "lost" its neck. Apparently up the bore WITH the bullet. (Yes, I checked the chamber and bore.)

Case #4 Third round fired with same load. Case neck separated and stuck in forward end (note taper) of chamber. The case neck was easily retrieved with a bronze bristle brush.

Please note, before I fired this ammo in 2003 all loaded cartridges appeared quite normal on the outside. Although scientifically interested in what was going on, I quit shooting out of concern for my own safety, and the condition of my rifle. When I got home I pulled the bullets from the remaining loaded rounds. Interestingly, when the bullets were pulled there was sometimes a "pop," either from very negative or positive air pressure in the case. Also, on the inside of the case between the bullet base and the powder there was considerable green, sticky crud. The bullet bases also showed considerable corrosion. The powder clumped pretty badly. If I remember correctly, some of the loaded rounds had been stored in plastic boxes with the bullets up and these (Remington brass) did not deteriorate QUITE as badly as those stored horizontally in typical 20-round cardboard boxes. Regardless, loading stick powder that has started to deteriorate is asking for trouble. Apparently, the acidic fumes and/or other chemical reactions served to corrode and/or make the brass very brittle.

Deteriorating powder can cause serious separations and splits in the cases. It is possible that excessive pressures could result. However, my chronograph data did NOT indicate unusually high velocities.

DO NOT LOAD STICK POWDER THAT IS STARTING TO DETERIORATE!!

# # # # # # # # #

Following are 3 pictures that show the effects of deteriorated powder on some .30-40 Krag ammo. I examined the ammo and took the pictures in 2007. I did not try to shoot any of it, and I did not record with the pictures the date it was originally loaded with the BL-32 stick powder. As you can see from the first picture all 10 rounds were not affected equally, but ALL were UNSAFE to fire, even the best-looking ones that could have had the outside of the case “cleaned up” of the tarnish. I was not going to fire any of this batch in my Krag rifle, and I sure as h*** would not try to pass them on to another Krag rifle shooter!!

Numbering from left to right, note that the #2 and #5 cases were so badly corroded that the bullets broke off with the case necks around them when they were pulled!! Case #6 was also badly corroded in the neck-shoulder area. The bullet had not yet been pulled. The other 7 cases showed some tarnish (#8 & #9 a fair amount of dark tarnish). However, cases #1, 3, 4, 7, & 10 showed very little tarnish, probably not enough to raise a red flag to the casual observer had they been in a separate group of loaded ammo.




This is a closeup of rounds #5 and #6 (as numbered from left to right in the first picture of all 10 rounds). You obviously could not shoot round #5, and anybody with common sense would not likely try to shoot #6. Please note the small spot of corrosion at just about the position of the top of the “solid web” of case #5. You can see it really well on case #6. And, yes, this corrosion (as well as the obvious corrosion at the base of the necks on cases #2 and #5) started from the inside of the cases. Firing a round with such corrosion that low on the case could be extremely dangerous.




This is a closeup of one of the best-looking rounds. I am not sure which one of the 10, but a casual observer of the loaded round would probably not have suspected what it looked like inside and the possible danger in firing it. Note the tarnish/corrosion on the outside of the case near the neck-shoulder junction. Note the green crud sticking to the inside of the case where the base of the bullet had been. Note also the powder grains “sticking” to the inside of the case just below where the base of the bullet had been.

Reply With Quote