Shotgun Hull Failures

The strain of firing takes a toll and somewhere in a repeated process of firing and reloading cycles a hull becomes unusable.  Once-fired hulls should be closely inspected for sign of brittleness, chips, fractures, loose basewads and loose brass heads.

The most dramatic looking failure is hull separation, when the the plastic tube disengages from the  metal head.   This failure frightens shooters, more than any other problem, but for the most part, a tube separation is caused by a separate, minor failure.

#1. Wear and tear has broken the bond between the steel head and the plastic tube – a more likely scenario with three-piece (Riefenhauser) hulls.

#2. The bend in the crimp has hooked the top edge of a dense shotcup.  This can happen when the top edge of an unfilled shotcup  is hooked into the bottom fold of the crimp.  When the load is fired, upward force driving the wad is transferred to the outer edges of the crimp, by the wad, instead of in the center, by the shot, where the crimp would simply "pop" open.  Something has to give and usually this force simply pulls the hull tube out from the brass section. If the hull is softened by the heat of the combustion the tube may stretch then tear just above the brass.

This scenario can’t happen in loads where pellets completely fill the shotcup or where a .030" overshot card is used.   Overshot cards ensure solid crimps, even if a crimp is imperfect or the payload slightly low.

The combination of stronger and thicker wads (such as steel hunting wads) and lower shot columns increase the likelihood of hull separations.

The shot column sits too low only if you have been lazy about adjusting the payload height.  Filler wads are required by most hunting loads, sitting just under the pellets. We would tell you exactly which wad for which load, but there are enough variables such as shot size that we cannot tell you definitively. Different loads will have different requirements and you will need to look at each load on a case by case basis.

A shotshell payload is at the proper height when it sits 1/4" below the top edge of an uncrimped hull.

© 2006 Ballistic Products Inc.

Shotshell, Hull Separating, Hull Separation, Hull Splitting, Hull Problems