Found this on the back cover of the July-August 1970 issue of "Handloader" magazine.
Some years back, I scored over a hundred of these magazines, in their publisher's binders The downside was that they came from the deceased estate of a long-term mentor and friend.
The entire series was released on CD ROM a few years back, and that makes searching faster, but it lacks the tactile and random nature of "tree-ware".
I have a box of these in 38 Special. Picked them up from an auction.
Lit one off in the basement with a S&W 36. Maybe 15 or 20 feet from a cinder block wall.
I can assure you, these are not toys! If a person was standing where that wall was, it would definitely ruin their day.
Pretty clear point of impact on that wall!