I will be picking up my (old) T/C Black Diamond with a new scope mounted.

In the past I had the hardest time sighting it in when it was new.
In the end I had to move the fiber optics sights a considerable amount to the left (they still look waaay off center) but it finally shoots true. I settled with 100/300 ( pyrodex pellets /sabot). I have never had to make any other changes when sighting in and I have tagged a few bucks with it in recent years.

My question(s):

If I wanted to change from Pyrodex to 777, should I do it now or should I keep the same load?
Should I expect any new problems sighting in with the scope considering the open sights had to be moved considerably to shoot dead-on?

Also, since my M/L shoots well using the existing fiber optics sights, I asked to keep them and have the scope mounted over them so I can now use both.

Thanks in advance....Jimmy[/align]