Win 760 is a double-base (nitrocellulose + nitroglycerine) spherical powder. It's not the fastest or the most accurate for any bullet I have used, but it has a wide range of applications. Jack-of-all-trades, master of none. My experience has shown me that ball / double-base powders generally burn dirtier than extruded single-base propellants, and that they ignite best using a Magnum primer.On a whim I decided to try some 40 yr. old Win. 760 powder that I had on hand. A load of 41.5 gns. gave 5-shot groups in the high .2's at an avg. vel. of 3,010 fps. All good except the powder is very dirty burning! The cases are showing carbon deposits all along the sides of the cases, whereas with the 4064 I would only get carbon fouling on the ctg. necks. Question is: is this common for 760, or could the powder have somehow changed characteristics with age? It looks OK, flows well & doesn't smell strange. I am even seeing carbon buildup on the face of the bolt edge, which shows me that I am getting a good amount of blow-by around the case.