T7, you might just be on the right track - this is a message that a Savage owner wrote:
I have occasionally had the concave part of the breechplug get so packed with powder that the primer fired through the center leaving 10-20grained of hardpacked powder filling the breechplug flush but not igniting. Imagine touching of 60-70 grains of smokeless in something that is designed for 50grains maximum charge.
Could this be the problem Toby ran up against?
The breech plug design of the savage is truly different than other that I use or have seen.