Primer sizes

[perry owens]

Sized and primed a batch of Starline 38-40s and loaded them with 4 different powder types and 2 different bullet alloys ready for a serious range session with my 1873 today. Happened to put a loaded round down on a flat surface and it rocked about. Doh!!! - I had used large rifle primers instead of large pistol. Luckily I found the mistake before I set out for the range 40 miles away.
While dismantling the faulty rounds I got to thinking. I know that rifle primers are harder than pistol primers to minimise firing pin penetration but why are they different cup heights? Also why does a round that was designed as a rifle round use large pistol primers?
Perry Owens

[Hobie]

That round has become, primarily, a revolver round and so the brass manufacturers have made the primer pockets for the pistol primers. I had the opposite problem with some ammo I got from JimT and so I'm shooting it in a S&W 1905 4th change.