IMR 4350 will work but I suspect you will find that H4350 works even better. I found a load for mine with H4350 that will be my go to load once I finish using up an 8lb container of IMR 4350. The IMR 4350 load will shoot in the .4s but the Hodgedon load shoots in the .2's! It is 43.0 Grains of H4350 behind a 140 Gr SMK at a COAL of 2.730"