Erupting shotshell

What causes this eruption in shotshells and is it something I should restore or toss?


I think the cause is likely the shot expanding due to oxidation. The telltale soft white oxide of lead is an indication this is the problem and may be present in your example. The wadding may also expand with moisture as well depending on the composition. Restoration may be as easy as replacing the shot charge with fresh pellets or just removing some to reduce the volume and repairing the top.


often the sides will also swell & the pellets can be seen pushing aginst the hull’s side. To just break at the top my guess is that it was dropped, but I could well be wrong in this case. (no pun intended)

The REM-UMC “erupted” shot shell was likely stored in humid conditions. As others have said the shot charge oxidized and expanded. A common ocurrance and in this case not worth a moment’s concern.

Incidentally, fired through a sound gun, the ejecta would be similar to a solid ball and would be good for penetring various objects, substituting for an axe when cutting a Christmas tree, etc. Ron

It is another good reason not to collect loaded shotshells !
The first reason being the tricks in shotshells are inside the case (special primer, inside head and so on) and therefore not seen in loaded ones !