Hi Kevin,
Those light 200gr loads should be in the 45 Colt case,no filler.
Use only the recommended starting loads.
Was reading about "duplex" loads-Please,don't do it.
Dick Casull,when he was developing loads,a couple powders didn't exist.So he used a "triplex" load.In one of my magazines, the writer told of how much of which powder.
Dick Casull destroyed several 45 frames.
Since there's 296,and H110 available,no need to experiment with "duplex/triplex" loads.
You sure can use "Ruger Only" in the 454.And then some !
Any "cowboy" loads can be fired in the Casull.
I agree with Gunnut45/454 on this.As the pressures are quite high with the regular 454 loads.
That's the reason why rifle primers are used.Most cases are now small rifle primer pockets.
I do have some made for the large rifle primers.
You can go over to the Freedom Arms website.At the very bottom, is "reloads".Save this either as an HTML,or better yet, as TXT.Or, by snail mail,request the loading sheet from them.
My best to you.