Huvius,
Yes, it does keep fouling down considerably. I have no issue firing the 20 round match and not needing to clean at all. Cases come out clean and don't need much cleaning either, although I do wet tumble them as soon as I get home. I found that less 4198 did give me fouling issues, particularly in the throat region. If I increased the 4198, I dropped the black charge back a little. Some of the writings I've read on duplex loads say that 1 grain of smokeless is roughly equivalent to 3 grains of black, so in this load I have 36 + 95 = 131 grain equivalent, pretty close to the original BP load.

I'll start another thread for the Swinburne.

Thanks.
DC