Before any of you old timers get worked up
Fast burning powders in applications where slow burners are called for is dangerous. Using slow burners in fast applications simply doesn't work well, but is only "dangerous" with regards to stuck/lodged bullets.
W231 is a very popular, fast burning target powder. It's great for .45, and likely why you are using it.
For alternatives in .30 Carbine, especially in a semi-auto gas-op rifle (I specify because I load .30 Carb for a revolver myself), other viable options:
H110 (same powder as your W296 with a different label on it)
...others, I'm sure. I have worked up some Blue Dot loads in a Ruger Blackhawk but wasn't happy with them and I'm not sure they'd produce a proper gas volume to run a carbine.