I haven't messed with the Sierra's, but with the A-max I can testify to the fact that if your impact velocity is over around 2700fps you going to have a mess to deal with. That said, I have loaded and shot hundreds of the 140gr .264 dia. A-Max's out of my daughters 6.5x55 with awesome results on both deer and hogs. The kicker is they are only starting out with a MV of 2550fps. I have also loaded and shot the 182gr .284 out of my 7mm RM loaded to 2800fps at the muzzle and out at 250 - 350yds they are still a bit rambunctious. In a .308 I have loaded and shot the 155gr A=Max at a MV of 2450, and it does wonderfully on even close up shots to deer and hogs. No big issues, and no bloodshot meat with behind the shoulder shots.
Now like I mentioned IF you keep your velocities down the A-Max has proven for me to be a decent hunting bullet in several calibers, but these were used after trying a multitude of other bullets and loads and then these simply being the ones with the best overall accuracy, with the parameters I needed them to be. I can easily shoot plenty of "better" bullets in everything but the 6.5, as it simply will not shoot anything else I have tried in the past dozen or so years of working on it. But that one is a limited example, and it was recently found to shoot he factory loaded Privi 139gr to best the A-Max and is now what we shoot in it.
In 95% of my other rifles I simply load and shoot the Rem CL's as they were cheap when I purchased them and they have been found to shoot very well in the rifles I have. Besides that, they simply work time and time again, but I still have to do my part.
Mike / TX