It just hit me. The data you mention for the 9.3x62 using the 250 Accubond and Varget, is 60.5 gr. I've look net wide to find such published data and only one place rewards me with 60.5 gr. Loaddata.com's data which references Handloader magazine, #250, Dec 2007. This shot from a CZ550, 23.6" barrel and pressure tested under 60k psi.
Now, I'm going to assume that is your load, published by you. If not, I apologize. I'd lay rewared where it is due. No other manufacture of load data, bullets, powder, etc, lists 60.5 gr of Varget of the 250 Accubond or any other 250 gr 9.3 bullet.
If it was indeed your data....
1. How did you come up with said data?
2. Did you use what we refer to as looking for typical pressure signs; ie, difficult bolt lift, velocity, measuring CHE, primer signs (poor signs), etc.?
3. Did you SWAG it? Educated guess? Pay a witch doctor for help?
4. Did you confer with ballistic reps at Nosler, Hodgdon or elsewhere?
5. Once you obtained the 60.5 gr data, I assume you had it pressure tested by Ramshot (?) since you seem to have a very good relationship with them.?
Did you notice an increase or decrease in accuracy with each increase in powder charge with this bullet/powder combination? My best accuracy with my Pre 64 M70 and 24" Pacnor barrel seemed to be in the 2400-2550 fps range with 3-shot groups running sub 1/4-1/2 MOA. As soon as I went above 2550 fps, groups opened up to 3/4 to 1.25 MOA; which is fine for it's intended purpose.
Basically, I'm wondering if you, like many of us out here in "Handloader Land", pus hed the published envelope a skootch more than the books say and use our years, possibly decades, of knowledge and experience?
Please don't interpret this post as a flaming arrow. I appreciate you knowledge and advice as a gunwriter.
Oh, and if you need to be politically correct, I understand. Do the best you can with your answers. Alan
