go here and read the data
http://recipes.alliantpowder.com/rg....auge=12&step=1

please forgive my previous two posts.....when someone tells me that this powder has a louder bark.......well.....here' s what you need...this is to alliant powders website and you can see for your self what the differences are.

Both can also be used for a magnum revolver powder.....I use Blue dot for all my heavy magnum shot shell and revolver loads except I use IMR 800-x in my 20 Ga.

For upland bird hunting with a 12 Ga either powder will do the trick.....just read the data and pick the powder that mostly does what you want it to do.

Regarding recoil.....the chamber psi is not relevant to recoil.....assuming a fixed gun....lets say a Remington 870, the factors that lead to felt recoil are two things only
1. The total weight of the ejecta....this means the weight of the BBs and the wad and the powder.
2. the velocity with which the ejecta leave the muzzle.

Regarding noise....the noise is a direct reflection of the chamber pressure as the ejecta is leaving the barrel