imr 4198 verses h4198

[rjhans53]

Cant find any h4198 but I have come across some imr 4198 will it interchange

[dannoboone]

According to reloading manuals which have loads for both,
IMR4198 gets higher pressures for the same amount of powder.
I wouldn't be fearful of using it, just start out with a
few grains less powder.

[kbrezlin]

I have shot the same charge of both out to 200 yards with no difference in the point of impact or group size. Just my experience. Last time it was available I just grabbed 8 pounds of H4198.

[jims]

I recall a quite small difference but not enough with my loads to be of a concern. I do not use huge loads.