I have some 2-3/4 all metal hulls for the 410, and I have found that I can fit 5, 95 grain .41 caliber round balls
ends up being 475 grains of lead, I am still calculating exactly how many over powder cards I need for proper crimp.
I guess the final weight will be right around 500 grains.
I don't really know where to start with a powder charge
for a 7/8 oz, or 4 ball load I was planning on 15 grains of 2400,
but for the 5 ball load, its going to be around 1-1/8 oz.
iv never heard of a 410 load that heavy. not even sure if its possible,
but I do think it would be interesting to try.
thanks.
Andrew.