I'm currently shooting 50 gr of H4198 over 10gr of SR4759. My rifle is a Encore 4570 conv. with Savage plug. I've located a 1lb can of IMR 4198 locally and considering giving it a try. H4198 is unavailable in my area. I would continue to duplex load but looking for help with charge weights of the IMR version. My primers are W209.