|
Imdarren,
I subscribe to "Handloader" and had seen that article on the 300 gr XTP loaded to the bottom cannelure. Before seeing that article, I had worked up a load using the pressure-ring measurement method. I was pleased to see that I had succeeded in stopping at a point a little less than Pearce's load. I was aiming for about 43,000 CUP which is the old pressure standard. Pearce seems to think he is getting about 46,000 psi. Neither Pearce's load nor mine was pressure tested. But, I note that the latest Speer manual lists loads for THEIR 300 gr bullet in ITS lower cannelure that are just a litte less than what I ended up with, and they are working to 36,000 psi.
With respect to my old 265 grain bullets, I already have data for them from a contemporary Hornady manual. That manual illustration shows a bullet with ony one cannelure. But, there seems to be a typo for the COAL in that manual, because it lists two different COALs for the same bullet in differrent sections of the manual. Strangely, the COAL in the rifle section is longer than the COAL in the pistol section. But, it looks like they just accidentally listed the same COAL as the 240 gr XTPs in the pistol section. As I wrote previously, that COAL puts the only cannelure on my bullets totally inside a trimmed case. So, I think that it is a typo in the pistol section. I have loaded these old 265s to the old manual max with no issues, so this is just a curiousity question from me.
SL1
SL1
|