quote] I personally have seen two early Remington 740's both in .270, heavily damaged...SUPPOSEDLY with factory ammo. One looked pretty good except for being locked up tight and one had a gap betwixt barrel and action face and a splintered wood forearm. Neither shooter admitted to handloads. The one that we were able to open eventually...the Federal brass was parted but did not look that bad, leading us to believe the rifle failed..with just a cursory inspection. I don't know what the final outcome was with Remington. Neither shooter was injured.[/quote]
I have cause to question factory pressures in some cartridge loadings. As most of us do, I have picked up range brass that is obviously in great shape. One of my last pickups was some Hornady Superformance in .270 Winchester. Brass appears new. It was on the ground, empty boxes in the trash can. Got both. At home looking it over, all 34 cases had obviously cratered primers. I mean a sharp ridge around the firing pin impact and flattened surface outside that. Boxes appeared new as well. Everything appeared to be factory fresh. But what pressure was required to flatten and crater primers in factory ammunition?
Also have 19 nickeled 7mmWSM Winchester factory loaded empty’s I got with a rifle so chambered. Once fired said the seller. Again, primer strikes are cratered with flattening of the remaining primer surface. In these two examples “tradition pressure signs” were exhibited in factory ammo. IIRC the 7mmWSM is a 65k cartridge like the .270. But again, what pressure is required to leave such an imprint. Inquiring minds. [/quote]
I’ve had similar observations, and this (in my mind) underscores why primer appearances aren’t not a good indicator of pressure. As an example, I received some PMC 6.5x55 brass that had been fired once in a Rem 700 (factory). Primers were flat (in fact had flowed some) but the pockets were almost as tight as new brass, and resized with no issues. Similarly, a friend gave me his once fired Federal Gold Medal Match .308 brass fired in a M110 look alike with a Match chamber. This brass wouldn’t hold the primers after one firing. The ammo was Federal’s factory loaded 168 Match loads.
I don’t believe either load was high pressure at all. The 6.5 ammo had soft primers, the .308 soft brass. Both appeared to be high pressure, if using primer/primer pockets as your sole indicator.
