Happy for a Winchester Model 21

[Cold Spring]

Thanks everyone for your kind comments. Yes that shot on Wednesday definitely got my attention. I've reloaded shotshells for over two decades now and never had anything like this happen. Here's some additional data.

The charge of Alliant E3 I use is relatively light and this morning just for test I loaded one Gun Club hull with 1.5 X that powder charge weight and the rest of the loading operations went as usual. The crimp looked typical and without a hint of a bulge. Then when I cut that shell apart I found the powder tightly compressed. Those of you who load light so-called "low pressure" shotgun loads with any powder should be aware of this. Incidentally that 1.5 X weight of Alliant E3 is way over the max shown in Alliant's loading data for my GC hull and components recipe.

One other possible factor: like most of my friends I use a "baffle" beneath the powder bottle to decrease the range of variability of the powder drops. Now, I don't know if it had anything to do with clumping of powder I left ~6 weeks in the press. You'll see in the last pic (looking down from the powder bottle) how there are two baffles that each block about 1/2 of the cross-section and cause the powder flow to reverse before getting to the powder bushing in the charge bar.