Hi to one and all. This site seems like a great resource for info. I skim read some pertinant threads but didn't find the exact info I was lookin' for ....which was specifically...how close is IMR4350 to H4350? If I am using H4350 will I be making a serious error by substituting that with an IMR4350 recipe(out of the book of course) for .270 win 130 gr bullet? If you know the answer I'd appreciate it and be glad to try to answer any ?'s anybody might have. I'm no reloading guru but I've lived, hunted, fished in the 49th for over 30 yrs. Thanks.