Not trying to discourage your work up with the 4350, but my experiences have mirrored Coyote Hunter's almost identically. The IMR-4831 load shot the 100gr BT's into 1/2" or less groups at 200yds 8 out of 10 times. The IMR-4350 load shot the Sierra's to close to the BT's to ever notice the difference. Funny but neither of the bullets would do good at all with the opposite powder.
Good luck