With great respect to those with more experience than I-
may I say that with my 500 Searcy the Aussie powders 2209 and 2213sc worked very well BUT after 30 odd rounds the action was full of unburnt powder.I did not have a problem with the functioning of the gun but I was worried I might.I still go to the trouble of R15 and a filler because it is very clean burning (in my rifle)