Bursting tracers


Below are a pair of red-tipped tracer rounds that have burst. It was the bullet bursting that in turn popped the case. Is this due to absorbtion of moisture in the tracer compound or is there some other chemistry at work?


Yes…that’s the way I have understood it…the hydrophilic nature (yes…moist absorption) of the tracer compound…there is probably a more technical chemical explanation…but it was the means to the end of the 30-06 frangible tracer with such a fragile bullet that could resist no tracer core expansion…yours is as dramatic as I have seen



I had a full box of 50 of these that looked exactly the same - what a disappointment. The box showed signs of water damage, so I’m sure that moisture was a major factor.


I have about 15 of these .45 ACP tracers, both red and green, that have all split. These cartridges were just stored in my cartridge cabinet, subject to normal humidity changes for Michigan, nothing drastic. I have had NO problems with .30-06 tracers of the same years, just the .45 ACP’s. Too bad, especially the far more rare green tracers from the 1920’s. I know of no way to prevent this damage. I think it might be caused by stress cracking of the bullet jacket which then allows humidity in to compound the swelling.


Hello Ron,

Why don’t you unload the ctges of you collection ?
And keep for each given caliber only one kind of each case material (brass, copper washed, green laquered steel case) and beside each case type put the different bullets .

Thus you avoid all the problems of powder reaction on the case and bullet.
Same about the bullets.

And furthermore you can not only see all the bullet details which are hidden usually by the case, but also the internal design of the case.

Another advantage is the fact it is less embarassing, because of the laws of the country where a collector lives, to have one case and ten loose bullets than to have ten loaded ctges !

Another fact is for example about the old ctges like European shutzen or old US ctges (sharps aso)
Most of the time you will never bet you right had on the fact the lead bullet is genuine because very often they are handloaded (more or less recently !).
Collecting cases and bullet separately, you can sleep quietly without wondering if the loading is original !!!

Conclusion : Safer about conservation of the ctges, more interesting because a full view of the design of the the bullet and of the internal case view, safer about laws, and avoiding the fact to have a lot of fakes (!


JP, I’ll meet you halfway. I’m not about to start pulling the bullets on everything in the collection, but … I went ahead and yanked the bullet out of one of the split cases pictured above to see just what it would take to remove the tracer compound from an unsplit bullet. It is a very hard compound as evidenced by the “crack” in the compound beneath the crack in the jacket. I don’t know enough about the stuff to go digging or chipping at it and don’t want to come up with another example for the “Dumb mistakes” thread that ran a year or two ago. What I decided in this case was that the split bullet and casing are a better illustration of the nature of this particular loading than a fully intact example. I then happily put them in the drawer as a perfectly legitimate specimen for the collection. A rationalization perhaps, but it does make sense to me.


Dry tracer compound shouldn’t be a problem to dig out. I was once told that you would have to put an oxy-acetylene torch to it to light it. If it has already oxidised then t shouldn’t even light at all. It is rounds with phosphorous in that are the dangerous ones.