Rapidrob wrote on Nov 4^th, 2018 at 12:28am:

I have never had to use a magnum primer. It is not a .50 BMG powder and would be very dangerous to use it as such. Any load over 75 grains in my magnum rifles really changes how it burns. But in cases from .223 to .300 Win Mag, the powder has worked very well for me. It is close to IMR-4350, just slightly slower, Not 7828 slow. In cases up to .30-06 and 7.62x54R, a load up to the shoulder of the case is just about right. You can go more but it is really not needed. Just never tightly compress the powder. It will spike like mad if too compressed. I have many,many loads that work well.

You must have the faster lot.  This slow lot only goes good with a booster that I put in the middle of the charge of 7383.  I've been using it in my K31 more than my Krags.  There were three loadings used in the spotter rifle, thus the three lots.  The slower stuff was for the tracer round that had a flashtube, plus a non-standard (hotter) 50BMG primer.  I haven't worked with any of the faster lots.  Thing is, the nitroguanidine coating needs to explode first.  That explosion consumes all the oxygen, then the remaining nitrocellulose burns without a flame making it flashless.