I'm not sure about the grain weight vs volumn but I recently tried the catch the powder when cutting thing. I was loading up 7 speed loaders for my kids deer hunt. I used an old cake pan to catch the excess powder and then measured how much was in the pan after 7 loads. I was surprized to see that it measured about 60 grains by volumn. If I had loaded 10 to 11I would have saved enough powder to make another load. For me that works out to 8 to 10 percent powder savings, not as small as I thought it would be. I may have to do some more testing but I think I'm going to start doing this more often.