ORIGINAL: cayugad
That Triple Se7en Winchester primer is really light compared to the others... very interesting as I shoot Winchester W209 for most or the Remington Kleenbore when I can get them on sale.
I beleive that theTriple seven primers were designed to be lighter to help offset the crud ring that comes with using triple seven powder. Also, some studies have shown that a "less hot" primer is often aids in accuracy(especially in inlines)