With that light load I still have to clean lead out of the barrel.
Dusk,
Slower velocity is not conducive to less leading. The two are not mutually compatible. There are too many factors that have to "jibe" in order to keep leading to a minimum, or none existent.
Case in point: If I remember correctly it is pinkemingeo (sp) that has had some 44 caliber bullets lead like crazy at 800fps while the same bullet driven to 1000fps shows no sign of leading at all.
Why? Well, bullet hardness mainly. Bullets that are too hard just will not obturate, period. If a bullet doesn't obturate, you will never get leading to go away, never.
Before you give up on that other company, or if you have some left over try this. Find a load that is safe with the bullet weight you have where the pressure is higher than the 3.5gr Bullseye load.
I AM NOT SUGGESTING THAT YOU INCREASE THE BULLSEYE LOAD AT ALL!
Why? Because in most manuals 3.5gr is the maximum load they suggest. That isn't enough of an increase in pressure to get a good test. Use another powder, if it is a 357mag firearm, find a low end load in that and see what happens.
The increase in pressure may need to be substantial depending on the hardness of the bullet.
I hope this makes sense. I know what I want to say, I just hope I am communicating it so you can understand.