Recommendation for search of "crud ring" is a good one. Quick answer is that 777 can form the ring mentioned. Depends a lot on the primer used, the rifle design (breechplug face configuration, primer channel length and shape, bore size relative to bullet/sabot used and a host of other variables). My Omega was so bad with 777 that I will not use that powder anymore. I now use Black Mag3 which is great powder but not very easy to find. I had to order mine and with hazmat fees the price is pretty high. 777 also has a sharp recoil characteristic that I do not like. I chronographed some 100gr. ffg 777 loads against 100gr. Black Mag3 and found the Black Mag3 was 300fps faster out of the muzzle and felt like less recoil. This was with a 300grain bullet in a sabot. My recommendation for powder is from best to worst (again this is my rifle and my opinion):BEST Black Mag3, American Pioneer Powder, Pyrodex and or real Black Powder fffg (both about equal), 777 is WORST. If you love 777 thats great; however, it is just not for me based on my experience.