No, I do not know about him. I did a search and think I found him. He shoots 200 Swift and 257 AI. Sounded like he was using IMR4350 powder. I have some of that. It can be incredibly accurate but is very narrow in load range. Have a friend who swears by Hodgdon H4350, he shoots 6.5 Creedmoor. Hodgdon owns the IMR powder too. But H4350 and IMR4350 are made in different plants. Very similar, but not exactly the same. (for all practical purposes, they are alike. Loyalists are very particular)
Most of the rifles I shoot are 30 caliber or larger.
I really like 30-30 for short range, Hornady 160 gr FTX bullets have done a lot of that one. Last I loaded, I used 29.7 gr Shooter’s World AR Plus. It is very close to what Hornady loads for that bullet.
Also like 308, Hornady 150 gr Interlock is a great load. Last I loaded was with 40.2 gr IMR3031. Very old but reliable powder.
I also have a long range 30-06 load. 208 grain Hornady A-Max using 54 gr Alliant Reloder 22. Have a 30-06 hunting load with Hornady 150gr Interlock and 43 gr IMR3031.
The guy I was hinting at was also a trapper for the state but his real claim was building rifles. Harold Broughton was his name, he passed away but his son build a fine rifle also, he’s building me a 204. I’ve still got a 6.5-06 his dad built me over 40 years ago.