Hi all,
I also havce a 6" Alfa.

I'm shootinh 148gn H&N Hollw base wadcutters.
I can't find any Herco to test but I do have Blue Dot...
4.0 to 4.5gns of Blue Dot seems accuracte but I need to do more tests to see if there's a "sweet spot".

I also have some Unique... 3.5 gns seems to work but again I have to test some different loads and chrono.

Once tested, I will post my results in case anyone is interested.

Meanwhile, please let me know if anyone tracks down some Herco and also if there is any other powder that works well.

I have also worked on the trigger and action and the trigger pull on mine is now much better than when I got it.

I echo the problem re primers sitting proud and jamming the cylinder rotation.
Will need to look into this a bit further, as well as modifying the loading press to hold the cylinder centrally and also put the press on a larger board to aid the leverage.

Any other observations anyone?
All in all not a bad pistol... good fun and the nearest we can get to a "proper" revolver at the moment.