I have a new Sendero 7 rem mag and have measured COAL TO 3.261. This seems a little short considering SAMMI length of 3.290. I have only shot 25 rounds so far but best accuracy seemed to come with .050 off the lands. With 64.5 grains of IMR7828. I'm still new to reloading rifle for accuracy so bear with me, maybe that is normal. I was hoping to load a little longer so that I could use more powder and achieve more velocity within max pressure. I did not bring the chrono on this day but the same load in my brothers SPS only made 2830fps. Is that a normal length for a factory chamber?