wildcatter wrote:I do, "Looks" like a good safe starting charge should be 25gr with a Speer 300 gr UCSP. You'll prolly make it to 30gr+ before you are done. But, thoroughly check the first shot round to make sure everything is to your std's..
..t
I'm glad you set me straight. Looking at translations from 460 S&W using 300MP, gave me the impression that a good starting point for our caliber would be about 34 gr. Alliant recommended 38 gr for the 460 S&W pushing the Speer 300 Gold Dot, so 34 seemed like a logical starting point for the 450b. Boy was I off.
Hopefully the next update to QL will include the 300-MP. The current data set as of December 2012 did not. I sure wish that the author of QL would produce a changelog file that potential upgrade customers could look at before committing to buy it and in the list, he would declare what new powders were being added. I imagine a lot of CFE223 fans would like to see that one supported as well. It seems to be catching on like wildfire in several calibers as well.
My secondary interest in 300-MP is for reloading the 7.62x40WT. Despite having a small step down neck, it seems to favor the same straight-walled powders as the 450b.
I got the bottle of 300-MP on the way home from work and am now set to do my first range run. In a strange twist of fate, actual springlike weather is forecast for this weekend (60s to 70s and sunny) and I'm entertaining some trigger time. We'll see if I can get the new lower ready by then and get out with both calibers to do some characterizing. It's been a long, cold, lonely winter and anticipation is getting the best of me.
Hoot