Winchester 209 primers are at the bottom of the heat list. As suggested, go with a magnum primer like the CCI or the Federal. This will give you a hotter burn and should burn off more of the powder.
I was at the range one day and I loaded and shot 24 loads without a patch and the accuracy was amazing. After the 24th load I had to run a patch down the barrel and was surprised at how clean the barrel was! Sure I could have kept shooting more loads without a patch!!!