BLACK GUNPOWDER FOR SALE FUNDAMENTALS EXPLAINED

I'll drop back several grains and perform up and find out what happens .I have and use alot in the 2400.Got 2 of the outdated Enfields No 1 MKIII's and would like to consider it in them also,have not loaded for them yet but beeing a rifle bored out to 410ga it'd be which i could bump them up a little bit far more,a regular 410 shotshell wont health