On the line with "Sean" in the reloading tech section at Hornady.
His explanation is that "their original test barrel was at or slightly over pressure at 67.4, but recently they replaced their test barrel and got significantly higher pressures, so revised the loading down." Both Bartlein barrels
I said, "so what's a guy like me to do, with 100 loaded rounds with 67.4? Pull them or keep rocking on if there's no pressure?"
He's talking to the guy "down in the lab"....will edit with results, if any, soon
ETA: He came back from the Lab (ballistician is a Retriever perhaps?) and said that the new test barrel is really "tight". He said that means chamber but I wonder if he didn't mean bore too. Says most of their reamers are Manson, SAAMI spec. (So how is it tight?) Says they had "several factory guns come through with very tight chambers" so they wanted to make sure their load recs will accommodate all chambers, made them more conservative. In regard to "what do I do?" He says if your load is under pressure, and you went higher and you know where pressure is in YOUR barrel, just keep rolling with 67.4"
He also mentioned that their factory ammo tends to be "right below pressure"
So, this is interesting since all their original velocity numbers were unrealistic despite running way hotter than they're currently recommending. How will this 7PRC cartridge be received now that we have yet another disappointment and another downward revision in the speed data?
Shoulda stayed with 7RM.