Sunday, October 30, 2011

Interesting Ammo - 12ga Tracer Ammo

One of the little known facts about being in the gun business is the staggering lack of variety that can sometimes be experienced. In the number of jobs I have performed over the years, nearly all activities can be summed up in about 5-6 different categories, over and over and over again.

For this reason, whenever I get a chance to come across something new, I like to take it apart and learn from it. This time I decided to share this experience with a bit of a photo tour.

Here is the current object of study. It's a somewhat elderly Winchester 12ga Tracer cartridge. While some eschew such novelties as useless fire danger, projectile designs that allow both the firer and observers to view the path the projectile takes, it has great utility in training, in target acquisition, and for diagnosing problems with the firearm.

Shotgun ammunition fills a very interesting niche legally in the United States, as it is greater than .60 caliber, but is exempt from destructive device classification (part of the NFA/GCA 68). An additional complication is occasionally provided by state laws. Under California law, tracer ammunition is banned, however there is a specific exemption for shotgun tracer ammunition under the California Dangerous Weapons Laws:

12301. (a) The term "destructive device," as used in this chapter, shall include any of the following weapons: (1) Any projectile containing any explosive or incendiary material or any other chemical substance, including, but not limited to, that which is commonly known as tracer or incendiary ammunition, except tracer ammunition manufactured for use in shotguns.

I started taking the round apart by the standard method (cutting off the folded portion) and slowly disassembling it. After taking the round apart, I laid out all the components. I used a bit of packing tape to keep the shot from rolling all over the table.


Shown above from left to right, the hull which includes a paper spacer around the powder charge (not shown), the powder charge, a sealing cup, the wad section, the tracer element, the shot cup, and the shot.

The tracer element is ignited by the main powder charge, by way of a hole through the sealing cup and the wad. The wad and tracer assembly is shown in detail here:

The nut underneath the tracer element is just to prop it up and show detail of the vent where the flames will come out. An interesting aspect of this design is the tracer element as a large aluminum ball, should be a close ballistic match to the individual shot pellets. However, obvious problem with this idea is you have a hole in the wad, while this is the only way to ignite the tracer element, it presents an obvious potential problem if the tracer element is blown out of the wad, this could have disastrous effects on the shot pattern.

Here is a photo of the assembled wad and tracer element:


Unfortunately, I only have the one sample, so I won't be able to provide any after-photos of a traced shot column flying through the sky. From the study of this round, and the obvious problems with setting fires, and possibly just not measuring up to the expected performance, make it obvious why this cartridge was never a marketing success. It is also likely this round was significantly more expensive than the other ammunition available at the time. Novel ammunition like this tends to come and go in cycles. I am sure at some point in the future something like this will be available again in the future. If you want some, keep your eyes peeled!

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