I've shot a LOT of this C&H powder, some Dupont, some Meteor made in Scotland. I would say that the Meteor was the worse of the bunch, but it all shot.
C&H of that time was down on power, that's for sure.
With the rubber stopper/pour spout, this is likely from the 50's or 60's. IIRC, we (Taylor and I) paid $0.98 for a pound of C&H back then, for our little cannons.
Those C&H 1 pound cans of 3F had rubber stopper/pour spouts.