Imr 4895 vs h4895

[farmbif]

I found a big box full of 158 grain jacketed round nose flat under the reloading bench and was thinking of using some in the 35 rem but going through the reloading books I have there is data for IMR4895 but none for H4895. How can I estimate a starting load using H4895 from the IMR4895 data

[Der Gebirgsjager]

Well, look around. H4895 info for .35 Rem. is certainly available. Have you tried Hogdon's website? The data for both is usually pretty close, with the H version tending to be a bit hotter. So if you can't find anything, back off two grains from the IMR loadings.

[Outpost75]

These days there is no difference between IMR and H4895, all comes from ADI in Australia.

Check the 4895 powder you have. If can is marked DuPont, it is pre-1977 and was made in Kenvil, NJ

If IMR but marked Made in Canada it was made by General-Dynamic Ordnance and Tactical Systems, in Valley Field, PQ prior to 1989

If IMR but marked Made in Australia it was made after 1989 made by Australian Defence Industries

With 158-grain jacketed bullets in the .35 Remington I don't think you can get enough 4895 of any manufacture in the case to get into trouble. I use 39 of current H and 40 grains of older IMR with a 200-grain bullet.

[shooter bob]

Hodgdon list different load data between the imr4895 and H4895 and different pressures.

[kenton]

Hodgdon list different load data between the imr4895 and H4895 and different pressures.

Interestingly enough showing the IMR version having a higher chamber pressure with a lower charge weight and velocity.

I would almost suspect that some of the data is older than the rest since the IMR data doesn't have a starting charge.

[Texas by God]

I have always treated them as equal but I never load at the red line anyway.

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[243winxb]

H4895 is used for Hodgdon youth loads. The powder charge can be safely down loaded.
Hodgdon 180 gr starting load of 35 grs H4895 will be a safe 158 gr starting load.

[303Guy]

I don't believe IMR 4895 and H4895 are the same. H4895 is an extreme powder while IMR 4895 is not.

[tomme boy]

They are NOT the same. One is black, IMR. And the other is the typical Hodgdon green grey looking. And they smell different when fired.

[Larry Gibson]

No, they are not the same powder as the IMR is made in Canada and the Hodgdon is made in Australia. However they have essentially the same burn rate as per many "burn rate" charts. I have found in pressure measuring both powders in the .308W with jacketed bullets of several lots each that the Hodgdon is usually a wee bit faster burning......to the tune that the Hodgdon will give the same psi and velocity with about 1/2 gr less powder in the 308W case with jacketed bullets. With cast bullets at normal cast bullet velocities the psi difference is negligible. As always, the load should be worked up to in any case.

Hodgdon 4895 has a bit smaller cuts of extruded powder and thus will give a higher load density in a given volume. It also meters a bit more uniformly in most powder throwers. As mentioned the Hodgdon 4895 is an "Extreme" powder meaning it is less sensitive to variance in ambient temperature extremes. I've found the Hodgdon to ignite and burn a bit more uniformly in colder temps, below freezing especially.

[John Boy]

They are almost, but not quite, the same. Velocities and pressures will vary as identical loads increase.
As to being "Extreme": H4895 was developed for, and is tested over, a broader range of temperatures than IMR4895.

[243winxb]

Skip the above BS and use H4895 like i said. Simple.

H4895 is used for Hodgdon youth loads. The powder charge can be safely down loaded.
Hodgdon 180 gr starting load of 35 grs H4895 will be a safe 158 gr starting load.

[Lloyd Smale]

ive used them both with the same loads in many guns over the years. If one creates more pressure ive never seen it. They like was said are still different colors so somethings different in them. My guess though is its like about any powder. It probably varies as much lot to lot as id does from one of those powders compared to the other.

[cwlongshot]

Its always safer to air on the side of possibles... Different is different. Safer that way as there is plenty of data for both why speculate??? TOTALLY AND COMPLETELY UNNECESSARY! Its more Fascinating to me why its even a QUESTION!??!

Different is different...

CW

[dakota]

I useH4895 in many cartridges

[atr]

I have always treated them as equal but I never load at the red line anyway.

I do the same thing and I have never had a problem.
I have gone to 95% of the maximum with no problems.

[1hole]

For a starting load I doubt it would make a difference. Above that, no matter the powder, it always becomes a process of observing for signs of excessive pressure. And "flattened primers" ain't it, especially for modest pressure lever action rounds like the .30-30 and .35 Rem. You could blow them from together before the primers tell you anything useful.

[303Guy]

That depends on what primers are being used. One should never depend on the primers!

Having said that, I have worked out a system for comparing pressures using primers. My primary system is following the load tables but I don't normally go anywhere near max loads. This system works great with Federal primers at higher pressure and great with Winchester primers at lower pressure. And that is where one can get into trouble relying on primers. My system is for low pressure cast and becomes meaningless with full power jacketed loads. I look at the firing pin indent, not the edge flattening. My objective is to compare low to medium cast boolit loads, not to guess at actual pressure.

[Tripplebeards]

All it takes is a phone call to Hodgdon and they’ll give you load data.

[JSteale]

My understanding is that IMR 4895 is temperature sensitive where as H4895 is not. This would explain experienced pressure differences not only with H4895 but with the same load of IMR 4895 but on cold days versus hot days. Of you check any burn rate chart for smokeless powders you will find IMR 4895 and H4895 either right next to each other or with N530 sandwiched between them. This means their burn rates are virtually identical. They are both solidly in the medium category of burn rate, IMR #90 and H4895 #91 out of 178 smokeless powders. Seems to me any pressure differences observed would be temperature related. Seems to me that H4598 is a better option for that reason. It's not affected by temperature the way IMR 4895 is.