So I have a question,
is shooting pyrodex in a inline a bad thing?
I understand the pros of 209 but is pyrodex going to ruin the gun?
This will be shot in a Knight Disc Extreme 52 Cal non jacket 209 conversion pre shut down gun.

It won't ruin a thing. The gun was made to shoot it.

Pyrodex is fine in inline rifles.

I figured i would ask since pyrodex is the rust your gun powder so they say!!

No, Pyrodex is perfect for your inline. It just doesn't burn as clean as BH209. But you still need to clean after every shooting session anyway. And on a positive note, the Pyrodex will ignite easier than BH209. Some inlines are finicky with the BH209.

Pyrodex is a very good consistent powder. It's also inexpensive when compared to other powders. Clean the gun and you will be OK.

make sure you scrub it out with very hot water and a bit of detergent and dry it and oil it the same day after you shoot it.

So long as you don't exceed the max charge you can safely shoot any of the BP subs or real BP.

Also remember to remove all traces of oil before loading. Do this with an alcohol swab, followed by a tight fitting dry patch.