I don’t know if this was any reason for the heavy primer crimps in
this blank cartridge, but I will mention that for cartridges, such as
blanks or primed cases, they don’t generate a lot of pressure, and
this can cause primer setback as the case is not held firmly against
the breech face.
I once need to make some dummies for a project, in .38 special. They
needed to have the spent primer in them. I had no problem removing
the bullet and powder, but figure the only way to have a spent primer in
them, conveniently, was to snap them in one of my revolvers. The first one
so “fired” lock up the cylinder tight as a drum. I finally figured out the cause,
extreme primer set back, and managed to free it easily by inserting a wood
dowel down the bore, into the cylinder and empty case, and tapping it with
a light plastic hammer, which reseated the primer and instantly freed the
cylinder.
It was the lack of set back when the case was fired that pushed the primer
partially out of the primer pocket, tight against the firing pin bushing, that locked
up the cylinder.
Blanks may not need those crimps - I just don’t know. Guess it would depend on
the amount of powder and pressure any specific blank had.
JLM