Gander - I had lots of issues getting caps to pop in my old CVA. I attribute it to a weak sear spring. Once I cleaned it, things improved, but still not to expectations, regardless of the caps used. The really good thing about the problem you had today is how steady it will make your shooting form. Nothing like a dropped hammer on a dead cap to show up flinch.
4 shots "still on the dirty bore" groups measured a little over 1", not to bad with the low light and the dirty bore
Not bad for a center fire even.