Hello: Speer's Manual #12 states that H4895 and IMR4895 are similar enough that, for any given load, one can be substituted for the other. Has anyone had any experience with this swap? Thanks - pagris.

I'll take your word for it that Speer's manual says that.

I'd never substitute unless there was definite proof that they are the same powder (and it's possible) but I'll only use Hodgden powder when it's specified in a manual and IMR when it's specified.

There is strong evidence that Win 760 and H-414 as well as Win 748 and H-335 are identical powders. But I'd never substitute!

The only substitution I'll make is H-4831-SC for H-4831 and then only because Hodgdon has said it's ok to substitute.

Loading data is free on the internet and in publications from Hodgdon, Alliant, and IMR....why chance it?

Of all the powders that have the same number designation, I have found that the IMR and Hodgdon 4895 powders are as close to being the same that I would not worry about it.

There are several versions of 4198, 4895, 4350, 4831, etc. But of all the powders that have the same designation, the two 4895's in question are about the closest of any.

I have used IMR 4895 and H 4895 enough to know that data for one is pretty close for the other.
Having said that, for some reason, I always get better accuracy from the H 4895 version.

I doubt that you will find any more difference between IMR 4895 and H 4895 than you might find between different lots of the same powder.

R F

In my experience, H4895 and IMR 4895 are very close, if not identical in burning characteristics, at least in the lots I have used. Those lots go back a ways though, and now that Hodgdon's stick powders are mostly coming from ADI in Austrailia and the IMR's are no longer Du Pont, I do not know if the same relationship holds. That said, the lot-to-lot variation of any stick powder can be significant, so when changing lots, always treat the new lot as an unknown until proven, whether of the same or a different brand.

IMR4895 is bulkier or slower than H4895. For cartridges like the .223 I find H to be a good powder, but IMR is unsuitable, giving very low velocities.

They are very close.

If you substitute one for the other, just back off a bit and work up to make sure of pressures...it's not complicated