Never shot a 140 Sierra, but RL25 and 140 BT's or AB's run about 3180-3200 out of my 26" barreled 264WM. They are accurate as heck as well, from a sporter weight rifle. It took a bit of tuning, but it runs pretty well. I am using CCI250, Nosler Brass and RL25 for both loads.
140 BT at 300 yards
140 PT and Retumbo
If elk are on the menu, I would look at the better built 140's, I think they would pay for themselves if you happen to connect with bigger bones..