IMR4350 or H4350

Bree243 · 11-26-2008, 06:22 AM

Can someone explain the differance between these two powders. I have used both. Is loading data for one interchangeable with the other? I see loads listed for both that are within half a grain or so. I have a lot of H4350 right now but some of my favorite 06 loads used IMR4350.

thndrchiken · 11-26-2008, 07:31 AM

They are similar, load data is not interchangable.

devil dog · 11-26-2008, 08:58 AM

H4350 is just slightly a faster burn rate of powder than the IMR4350, I would not recomend swapping data of one to the other, use your books and brain, start at min and work your way up looking for preasure signs as you go, the outcome may not be worth the risk!. One of my books show a load for a 168gr starting at 57.5gr of IMR4350, another shows starting at 49.3 for the H4350, it max load is 56.1gr which is 1.4gr under start for the IMR.

kelbro · 11-27-2008, 09:16 PM

Know what you mean... I have great loads for the '06 with IMR4350 but the best load for my 243 uses H4350 and my 270 doesn't like either!

I think that if you have a good load with either, you could work up a load with the other one that would work just as well. Start low and work up looking for pressure signs.