Decrease pellet weight by 80 grains reduce powder by ?

[grumpy1]

I am relatively new to reloading so I always follow recipes exactly, now I want to change to a lighter shot load. Was loading 9-00 buckshot (weight 484gr) got a mold that casts .31 diameter weight 403 grains that fit in wad ok but the weight difference is 80 grains. Do I reduce the powder by how much. This is the recipe I used for the 00 buckshot, 30 grains HS-6 Win209 primer WAA12 wad

[megasupermagnum]

I don't know that I would reduce that load any, and less than an ounce is getting to be pretty light for HS6, unless you want high velocities. If you switch to a faster powder, you can keep velocities down. I see load data in a gold medal hull, win 209, WAA12 wad, and 700X for 1 ounce of shot (438 grains). 15.5 grains @ 1,100 fps up to 18.5 grains @ 1,250 fps.

[GhostHawk]

Increase of load weight means you need to lower charge to keep pressures lower.

Decrease of load weight = less pressure. So If I lowered it at all it would not be much.
I might add some buffer to help make up some of that weight.

I also like loading .30-31 caliber balls over 00. Everything just works better. Pour in 9 balls and they self stack.