357,
The charge of Staball6.5 that I'm using with that 65 grain Sierra is 40.5 grains which is probably near maximum. I extrapolated that from the hodgdon manual. They show 40.6 with the 63 grain Sierra. I'm using older Winchester brass that's been annealed with federal match primers. Still no chrono data yet, I don't expect super high velocities out of the Teeker as it only has a 22" barrel. Which is fine as I really bought it due to the 8" twisted barrel and it's ability to handle the heavier Boolits. From that limited example of one, it seems that the expansion of the 65 grain Sierra was adequate but not explosive, but that was a large specimen and they will soak up a lot of lead without coming apart like a prairie dog as you know. I do have a jug of H414 and have used it with good success with a different 250 and also my current Swift, have not tried it in this rifle yet.
The usual disclaimer applies to the novices out there that this was safe in my rifle….. yada yada yada.
Gary