stubble, I won't dispute your results, I was just working from my own experiences. Several years ago, I worked with Nosler and their ballistic tip bullets. Seems that I could push their 140 gr 7mm BT bullet beyond their speed window with a 7mm Rem Mag. They recorded numerious failures from individuals across the crountry and ended up redesigning the BT bullet. Back then, in my testing, I believed the bullets were actually failing in air due to the velosity. I know todays BT is a completely different bullet, but I still worry that a full power load in a 300 RUM, you can push a 180 gr bullet pretty hard. And a 165 gr, churning 3400-3500 fps, i think, is outside of the BT's window of performance. I just think at the speeds generated by the 300RUM, non-rapid expansion bullets are better suited. Just my $.02.