H4350 VS IMR4350

[JMB 1911]

I am having issues finding H4350 my Lyman manual shows very similar performance with IMR and I think all IMR powders are suppose to have some copper fouling inhibitor in them. So what is the difference does anyone have a history with the IMR powders?

 

[Savage 12BVSS]

I asked the same basic question a couple weeks ago. Think you will find your answers if you search it or just go back a few pages, Good Shooting Dave

 

[JMB 1911]

I went back 6 pages and didn't see it

 

[West Calamus]

I am having issues finding H4350 my Lyman manual shows very similar performance with IMR and I think all IMR powders are suppose to have some copper fouling inhibitor in them. So what is the difference does anyone have a history with the IMR powders?

The H powders have more temperature stability then the IMR powders. You may see more varying results on a IMR if shot at 20 degrees versus shooting in 90 degree weather then you would with a H powder. I use the H in all my 308 length cases and IMR in my Mag or 30-06 length case. Don't ask me why, no particular reason just that is what my rifles seem to prefer. The H powder is the newer designed powder then the Improved Military Rifle powder. The H is a slighty slower burning powder.

 

[jjmp]

When I started out reloading I used imr4350 & it worked good , that's a long time back , now I'm very happy with h brand , the importer H doesn't make the powder it's made down under , as for them being alike I don't think so , burn charts are guides nothing more ,? You say ,just to manny variables and I don't think they have changed the formula one bit in imr's 4350 , don't get me wrong it's good stuff but there's better and think your talking about Enrons copper fighting addatives that are only in Enrons Imr powders , the importer H is saying Enrons /IMR 4451 is close to H4350 by all counts on paper it looks good ,but it makes higher pressure from the little bit I've compared them ,more personal testing is needed . Cheers jmho.

 

[West Calamus]

I went back 6 pages and didn't see it

Look up and read the thread "H4831 for 300win mag?" There is some good discussion on different powders. It is under the reloading forum.

 

[BallisticsGuy]

Ok, I'll post this again since your search button is broken.

IMR 4350 and H4350 ARE NOT THE SAME POWDER OR ANYTHING LIKE THE SAME. Only the numbers are in common. IMR4350 is substantially faster burning. IMR4350 powder DOES NOT contain a copper remover. You're thinking about the new Enduron line of IMR powders, not their legacy powders.

H4350 is very temp stable. IMR4350 is not.

If you get 1 granule of IMR4350 in a load of H4350 you'll get to throw that piece of brass away when the primer falls out and you might get to throw the extractor or the bolt away too. DO NOT MIX EVEN 1 GRANULE OF IMR4350 INTO AN H4350 LOAD. Ask me how I know.

An IMR4350 load will produce higher peak pressures than an otherwise identical H4350 load. I have successfully substituted IMR for H by dropping 1-1.5 grains per 40 grains of total charge weight. I do not recommend being as flippant as I was. Probably start 2 grains lower with IMR4350.

They really are different. Just because one CAN work in the loads the other works best in doesn't mean it's a good idea. High peak pressures and low velocities are the rewards for using too fast a powder.

 

[Pa Grizz]

I have used IMR 4350 for 45 years in seven calibers.The only time there was a change when it went from Dupont to IMR. I lost an average of 100 FPS in each of them .I still have some Dupont I use for hunting

 

[West Calamus]

Ok, I'll post this again since your search button is broken.

IMR 4350 and H4350 ARE NOT THE SAME POWDER OR ANYTHING LIKE THE SAME. Only the numbers are in common. IMR4350 is substantially faster burning. IMR4350 powder DOES NOT contain a copper remover. You're thinking about the new Enduron line of IMR powders, not their legacy powders.

H4350 is very temp stable. IMR4350 is not.

If you get 1 granule of IMR4350 in a load of H4350 you'll get to throw that piece of brass away when the primer falls out and you might get to throw the extractor or the bolt away too. DO NOT MIX EVEN 1 GRANULE OF IMR4350 INTO AN H4350 LOAD. Ask me how I know.

An IMR4350 load will produce higher peak pressures than an otherwise identical H4350 load. I have successfully substituted IMR for H by dropping 1-1.5 grains per 40 grains of total charge weight. I do not recommend being as flippant as I was. Probably start 2 grains lower with IMR4350.

They really are different. Just because one CAN work in the loads the other works best in doesn't mean it's a good idea. High peak pressures and low velocities are the rewards for using too fast a powder.

I do not think anyone was implying that the 2 powders were the same and could be loaded gr for gr as such. As far as IMR 4350 being substantially faster you are flat out wrong. Tenth edition of Hornaday reloading Manuel shows Imr at 125 th and H 4350 at 127 th fastest burning powder. I see that as the two powders having virtually the same burn rate. I am not really interested in your reply.

 

[JMB 1911]

My question was more is it a reasonable substitute. I wouldn't think they were identical and I would certainly never mix 2 powders

 

[West Calamus]

My question was more is it a reasonable substitute. I wouldn't think they were identical and I would certainly never mix 2 powders

Yes it is a reasonable substitute. What is the caliber and weight of the bullet you are using. The faster burning powders with a heavy bullet per caliber will give more recoil but may be more accurate.

 

[JMB 1911]

6.5 Creedmoor 147 grain horandy

 

[West Calamus]

6.5 Creedmoor 147 grain horandy

I'm steeping out of this thread since I'm sure there is some creed guys that know much more then I do on reloading for a 6.5 C. Best of luck.

 

[Litrfoot]

There are 2 powders i find perfect for the 6.5 Creedmoor, H4350 and RL-16. You'll get a little more speed out of RL-16 but it is also a little dirty. Nevertheless both are my go to powder for that cartridge.