Originally Posted by WV Sendero
I came across this when trying to answer some of my own questions so I thought I would post the link. Hopefully this is useful for others too. This is not my data so I can't attest to the accuracy but here it is: Primer Testing Reference
Precision Shooting did a similar test a few years back (no Russian primers tested), and it seems to me that there have been other tests as well. I'd liked to have seen a compairison done with a smale flash hole verses a standard flash hole to see if it had any serious effects.