When I first got my Omega with the stock 209 plug, it was practically unshootable. Only VERY careful manipulation of the cleaning rod kept it from getting stuck in the crud ring; numerous times I had to pull the plug or otherwise mess around for A LONG TIME to get to the next shot.
I switched to the 25 ACP. I don't believe they even sell the 22 Hornet anymore, as it required trimming all of the cases you bought. The 25 ACP uses the cases exactly as they come, no messing around. The Omega closes a little tight on a new casing, but after that first time they are right on.
The crud ring is now gone for all practical purposes. There is still an increased layer of fouling in the 2-3 inches of the breech, but nothing not easily cleaned out with a spit patch. IMHO, this conversion made 777 feasible in my gun. Without the conversion, I would have had to revert to pyrodex...which I hated due to the cleanup hassle.