I've tried 110 gr ttsx at the range only. I was getting 3400 fps with "if my memory serves me right" 61 grains of H4831sc. Accuracy was good. I've done a little research and there are claims of upto 3500 fps with the right powder. My next loads will be with RL26, with that powder I was getting 3200 fps with 130 gr ttsx. I'm thinking RL26 will be the top powder for the 270 for velocity. With your rifle zeroed at 300 yds there should be very little hold over to 400 yds. Your correct it turns your 270 into a 257 bee. I've got a kimber mountain ascent 270 that weighs barely over 6lbs scoped. Having a rifle in that weight class with that kind of velocity makes an awesome mountain rifle especially when you consider recoil. JMO.