by No1Mk3 » 15 Apr 2025, 11:48 am
The other consideration when using approximations of burn rates from tables is that a given weight of one makers powder, whilst having similar burn rates, may produce completely different gas volumes form another makers powder and changing the time that peak pressures develop and last. This is why it is always a good idea to start a couple of grains lower when using such tables. Another point to think on is that all load data is derived under very specific and controlled laboratory conditions regarding powder, primer, chamber size, barrel size, temperature, humidity, cartridge case volume etc. Change even one of those variables and the data is no longer valid, so all published data is given with these variables in mind to make it safe under a wide range of reloading and firing conditions, ergo the data is NOT set in stone so published starting and max loads again consider these things. Finally, maximum loads are published in different books as determined by Corporate Lawyers seeking to minimize the risk of lawsuits, and is SOMETIMES less than optimal. So you will hear some shooters talking about using loads quite a bit over all published data, just remember those of us who do this have a good deal of experience and have reached such loads by careful experimentation in specific rifles using specific components and with consideration of weather conditions. As the others have stated, use a powder makers/sellers (only a very few companies actually make powder) data and Burn Rate tables as a guide with the idea of starting a few (2 - 3 typically) grains lower than starting to see how things go in your rifle, Cheers,