Not exactly. I am saying this is indeed how the 'crush' happens, but i don't necessarily feel it.

The caliper tell's me what the 'crush' is. For example, the table you posted the other day had the STS primer being 0.294" long. When i close my Accura with it's current breech plug, i cannot really feel any 'crush'. However, when i open the breech, and then remove the unfired STS, it will measure 0.291". This is the 'crush' that makes for zero blow by, a shiny clean spent primer, and clean scope bottoms. Myself, i cannot feel this 'crush' when i put the Accura into battery, however, i can feel it when i put my Omega into battery.

What was happening to the CVA guy, is, he was 'smushing' the W209 primer. They were sticking, and leaking, because they were deformed by being 'smushed'. In that instance, they were forced tight to the side wall of the primer pocket, not just the shelf. Of course this is only conjecture on my part; i wasn't consulted nor was i there, but it is the only logical explanation i can come to. When i received the plug, and measured it, and examined the primer pocket, my inspection verified what i already was certain of; the primer pocket was not too deep.