With the generational spread, I feel that testing protocols, equipment and testing goals cause more variance in data that difference in powders. I am very cautious with data from any source and vintage. I consider all loading books of whatever vintage to be valuable sources of information, but realize the limitations.

Cast bullets in rifles in general work at lower pressures and any slight change is powders are not likely to get a fellow into pressure problems. I assume you would use starting loads and go up.

In rifle cast bullet loads, 4227 and 2400 are very good and have similar (not same) burning rates, but difference in bulk. I use them both with 2400 getting the nod as I also use it in magnum handgun loads.

As a rule of thumb, I used 2400, 4227 and 4759 for loads up to about 1.8K fps. Above that I use a slower medium burning powder such as 3031, 4895 and the like.

Another problem I have now is I'm getting low on standard LP primers and wanted to load up a bunch of mid range cast 41's for the Bisley I just picked up. I have several thousand LP mag primers though.