Why no crud ring with 777 and #11 caps?

[robertb]

I have a Knight MK-85 that's been good to me since the early 90s. I started with Pyrodex and moved to loose 777 when it came out. I've always use #11 caps. Many people started mentioning crud rings with 777 while using 209 primers. However, I have never experienced a crud rind with the Knight and with #11 caps.

With that said, why does 209s produce crud rings with 777 but a #11 cap doesn't. Is is due to the 209 being hotter?

 

[Idaholewis]

Due to the 209 being MUCH Hotter, and possibly Carbon from the 209? I haven’t shot a lot of Triple Seven but i have shot enough of it to witness the Crud Ring difference between 209s and #11 Caps, and there is a BIG difference