Back in the day, long before anyone called it the 260, I had built a 243 necked up to 260 "6.5mm" and it was deadly on grounhogs and fox as far as you could see them using a lot of 4064 powder. This rifle had a twist of 1 in 11.5 inches just to shoot light bullets, so I don;t know how a factory 269 will work with light bullets.
BD