As others have mentioned, I have heard that the published load data for the 300 Savage is very mild in part by all of the model 99s floating around. So, nothing wrong with working up to published data.
I am certainly not an expert on loading for the model 99, but here is what worked in one I Ioaded for last year. Hornaday brass. Both loads shot right at 1.0" groups.
42.0g Varget, 150 SST, 2.600", 2,600 FPS
39.0g H4895, 165 BTPS, 2.610", 2,400 FPS (estimated)
