rjc324:  I have no direct experience with these 'cast bullet' loads from my old Lyman Handbook.  They were for 'gas check' bullets, but, may be workable with your 150 grain plated bullets.

bullet #311466 (150gr. GC) 15 grains IMR-4759 = 1510 fps.

bullet #311466 (150gr. GC) 16 grains #2400 = 1550 fps.

bullet #311466 (150gr. GC) 17 grains IMR-4227 = 1555 fps.

bullet #311466 (150gr. GC) 18 grains IMR-4198 = 1620 fps

I am always reluctant to post any reloading data and these loads are from a handbook published in the 1960s.  You might want to cross check with data on the 'Cast Boolit Forum'.

You didn't mention what powders you had available to use.  Those plated bullets are still relatively soft, I think they're pure lead under the plating. Castpics has some 30-40 data.  Blue Dot has worked good for me, start around 15gr.

Nothing wrong with Green Dot for cost-effective non-jacketed loads in the 13-1500 fps class. 10 to 13 grains will do the job. Of course this is pretty low-density, so avoiding double charges is critical.

Check Lyman CB handbook, 3rd edition, for verification with similar-capacity cartridges .308 Win, .303 Brit. and 7.65 Mauser. Note listed pressures. (Never accept load data from dodgy strangers!)

Good luck with that. 4227 doesn't really ignite or burn well at the low density and pressure you'll probably have to employ with those relatively-soft plated bullets. Green Dot, a double-base powder with a good proportion of nitroglycerin, is more likely to ignite and burn nicely at low density/pressure.

Save the 4227 for small, high-intensity cartridges like the .22 Hornet.

Thanks Butlersrangers, tried 17.0 Grains of 4227 and it worked flawlessly, was able to keep 1" groups offhand at 50 yards.
I might try the Greendot next for a comparison.

Fine on both counts. Feels like a .22 in the recoil department.
Bore was as clean as if I had shot the usual 180 Gr Round Nose.