I’ve used TSXs with great success in the ‘06 (168) and the 375 (270) and the TTSX (a 140) in a 284. But one time I used a 150-gr TTSX in the 284 and I killed a good whitetail buck at about 500 yards. It was the day after a blizzard in the Sandhills area of Nebraska and the temp was about -20* to -25*. It was bitter.
The bullet was over R17 and had chrono'd consistently about 2950 mv. The buck barely traveled thirty yards but the entrance and exit were not much bigger than bullet diameter as expansion appeared nil and double-nil. Due to the cold I didn’t do too much searching out of the bullet’s path through the chest.
I have wondered if the cold affected the load (R17 — ?100-200 fps slower) resulting in a much slower impact velocity than expected or if I may have met that rare and extra tough bullet. However, refuting that first thought is that the bullet hit where I was aiming at 500 based on the higher chrono’d mv.
Even though you don’t exactly know the reason why, one remembers these things.
But this seems to be an aberration at least in my experience and is probably much further than your grandson will shoot anyway.
