H4198 This Extreme series extruded propellant has gone through some changes since its inception while maintaining the identical burning speed of the past. The kernels were shortened to improve metering and necessary elements were added to make it insensitive to hot or cold temperatures. H4198 is outstanding in cartridges like the 222 Remington, 444 Marlin and the 7.62 X 39. Available in 1 lb. and 8 lb. containers.