Sorry to hear about your issues. Most Omega's seem to shoot really well. Hard to say for sure what the issue is, but something isn't right. I know mine would shoot MOA all day long with several different loads if I did my part.

I have some unexpected expenses come up and may be selling a few of my Knights if you are interested. One is a new old stock Disc Elite .50 , the other is a used/like new Disc Extreme .45. Both are stainless/black. All the Knights I have drive tacks and you can use whatever powder you like.