As pointed out earlier, military cases are thicker and will not accept 'as much' powder as commercial cases. Likewise, all commercial cases are not created equal and will display quite a variance in the total quantity of a given powder that can be contained. Your stick powders are much more difficult to 'pack' than are the ball powders and spherical powders. And, yes, all powder scales are not created equal. A few years ago, I read about that and prompty placed a reputable mfg's bullet on the scale. Hmm, a 100gr JSP weighed in at 96gr. Several were tried and all 'weighed' the same. I went to the Trading Post and picked up a set of checking weights. At the charge range I was using, the scale was 3gr light or about 7% - a very dangerous situation if I were trying for a 'book' max charge, as opposed to the 'accurate' charge to suit the purpose of the cartridge. Add to that the scale was not consistent at 7% light across the range of the scale and was really unpredictable. The company was long out of production, and the scale became a paper weight.
As a case in point, my 8x57 cases, as a general rule, will not contain a 'book' max charge of IMR4350, but does wonders with IMR3031(compressed) and is simply outstanding with BallC2 and no compression.
I don't load for 358's, but my 356W likes 40gr of H4198 with the 200Rem SPCL @ 2400fps. I've also loaded 45gr of IMR4064 behind the 200RemSPCL, but have not chronographed them as yet.
This is the fun of handloading for me - making it happen.
Regards,
Sweetwater