The new Nosler reloading manual #9 shows their highest 250 grain load as 2643 fps using 58 gr W748
Strangely their top load with the 358 Norma was only 2628 fps with IMR 4350
I would guess they put a little more time and effort into working with the Whelen as they show its case had a water capacity of 78 grains vrs the Whelen's 62.2
458Win,
The 358 Norma data goes all the way back to #4, from 1996, which was, I think, the 1st Nosler manual to have 35-250gr data. It's unchanged in any way except that #4 had RL12 data for 6 options rather than the same 5 options printed in later manuals. The 358 Norma data simply has not been reshot, only reprinted. Since somewhat the same powders seem to be optimal between 35 Whelen & 358 Norma, I've begun increasing the newest & bestest in the larger case, but $$, availability of components, & hot weather has put kind of a heavy brake on the project the last few months. PP2000MR ran out of case space in the Norma before pressure with 200s, but was showing promise with 225s. Will have to dig up notes to see about 250s, as not sure they were tested yet.
Edit... Just looked at the records & in a 22" 358 Norma, PP2000MR got to 85.5 gr @ 3200fps with the 200s case full no pressure sign & to 3150fps with 85 gr & 225 Sierras with a slight ejector mark so backed it off to 84 gr. @ 3120fps. With 250s IMR4451 did 2760fps @78 gr. Case full, but can add another gr or 2 to pass 2800fps I'm sure. Groups look promising with most right around an inch @ 100 yds. Will be trying the PP2000MR with 250s when I get around to it.
I have some PP Varmint on the way which hopefully will do better with the 200s in both Whelen & Norma, although I did get to 3000fps in the 22" Whelen with PP2000MR in some Lapua '06 brass necked up.
