You don't need a different brand of powder.

You need either 2-1/2" or 3" patches that are wetter than what you're using -- also need a bore brush instead of a jag to remove that crud. Swab after every 2nd shot. Also make sure all oils & lubes are removed from the bore before loading. Straight 91% rubbing alcohol gets that job done. Alky also makes a good swabbing agent. So does Windex. You also need a weaker 209 primer. Buy the regular CCI's when using 777 pellets. If youwould switch to loose powder, then you coulduse Remington Kleanboresand/or Winchester Triple Se7en 209 primers. They really diminish the crud ring.

Loose powder has it's advantages when using 777 powder that exhibits a crud ring.