777 which I use in my Triumph leaves a lot of hard crud even if you dont get a crud ring it is also harder to ignite,
on the other hand it is very strong [has more potential enegry] and very reliable.
I shot APP-FF in the Omega for two years and it is very clean and low pressure by the strain gage but you need about 10% more powder to equal RS results; I quit using it because I got 3 bad cans [very frustrating] the bad stuff shoots all over the place with a very wide range of velocities and you can not be sure whats wrong till you try another can or a different powder. Lee