It sure pays to test. I'd hate to turn necks I didn't need to. And though match chambers might repsond better, I've found its a barrel by barrel deal. Unless the brass is bad. Which may be an issue with 300RUM brass. Have not heard great things about it. Will see when I get my 338 Edge done. I hope its better by then.....

Of course turning 100 necks for hunting isn't a big deal. Turning 1000 for matches sucks.

Jeff