Something in the area of 12 grains of Unique will make a good light load.

If you want to load it to half as you stated go to IMR SR4759

Hey Flying Ace,
I have used 17.5 gr. Unique with a 110gr. carbine bullet for a long time now. Reasoning being is that I wanted something that would shoot to same point of impact as full power 150 gr. deer loads out to around 50 yds. or so. I'm not arguing about fillers but have not used any and used magnum primers...never had a misfire. Use alot of that BlueDot in my .444 Marlin and .30-30 Win. Is a real great powder for cast bullets in both of those. Another great powder I have used is RX-7. I use 38gr. with a 30-30 150 grainer. Jim Carmichael wrote a nice article about this awhile back in Handloader called "Light Loads for Light Rifles". I shot grey squirrels with that 110 gr. carbine bullet load by the way & did less damage to the meat than my buddy with his Ruger 10-22 and hollow points.
Yup,
Newtire