I was taught that the primer was a good indicator of pressure. A very much flattened out primer indicated very a high pressure.
I took my 12FV .223 Savage and my home made rest to the range today. I had purchased a quantity of Winchester and Federal ammo. The Federal ammo worked quite well while the Winchester ammo is not near as accurate. When inspecting the spent cases I noticed that some of the Winchester primers had flattened out considerably more than others. Is this just plain old poor quality?