IMR4895 vs. H4895 for .223rem 77gr SMK?

Redhook · December 6, 2004, 03:53 AM

I know that there have been many claims in the past that IMR 4895 is very similar to H4895. And I wonder now really how similar they are now that Hodgdon owns IMR?

My friend and I keep a lot of IMR 4895 for loading .308win and I'm looking to load .223rem 77gr SMK's using the IMR. But, my loading manuals only reference H4895 for 77gr's. So, is it possible to use the IMR as a substitute? Or am I looking for trouble even if I back off 10%?

Jim Watson · December 6, 2004, 09:42 AM

Once upon a time, H4895 WAS IMR4895. Hodgdon was selling surplus 4895 before DuPont ever put it out for the retail market. When surplus stocks ran out, Hodgdon had H4895 made by ICI in Scotland. Now they have it made by ADI in Australia. They have tried to keep the burning rate constant for the past 60 years of surplus and contract supplies but they are not all the same stuff. But they are close enough that you can do the -10% starting load procedure to go from one to the other.

Or call up Sierra and ask them. Their service line has information that hasn't made it into the manuals yet.

Hodgdon now owns IMR Powder of New York, which is only the US importer and distributor. IMR powder is manufactured in Canada and Hodgdon did not buy the factory. IMR4895 and H4895 are made on opposite sides of the world by different processes.

Tim R · December 8, 2004, 08:04 AM

Lets back this pony up here for a bit. You can use H 4895 with IMR 4895 data, but not the other way around.

December 6, 2004, 03:53 AM	#1
Redhook Senior Member Join Date: January 25, 2001 Posts: 254	IMR4895 vs. H4895 for .223rem 77gr SMK? I know that there have been many claims in the past that IMR 4895 is very similar to H4895. And I wonder now really how similar they are now that Hodgdon owns IMR? My friend and I keep a lot of IMR 4895 for loading .308win and I'm looking to load .223rem 77gr SMK's using the IMR. But, my loading manuals only reference H4895 for 77gr's. So, is it possible to use the IMR as a substitute? Or am I looking for trouble even if I back off 10%?

December 8, 2004, 08:04 AM	#3
Tim R Senior Member Join Date: November 30, 2004 Location: God's side of Washington State Posts: 1,601	Lets back this pony up here for a bit. You can use H 4895 with IMR 4895 data, but not the other way around. __________________ God Bless our Troops especially our Snipers.

December 6, 2004, 09:42 AM	#2
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 18,537	Once upon a time, H4895 WAS IMR4895. Hodgdon was selling surplus 4895 before DuPont ever put it out for the retail market. When surplus stocks ran out, Hodgdon had H4895 made by ICI in Scotland. Now they have it made by ADI in Australia. They have tried to keep the burning rate constant for the past 60 years of surplus and contract supplies but they are not all the same stuff. But they are close enough that you can do the -10% starting load procedure to go from one to the other. Or call up Sierra and ask them. Their service line has information that hasn't made it into the manuals yet. Hodgdon now owns IMR Powder of New York, which is only the US importer and distributor. IMR powder is manufactured in Canada and Hodgdon did not buy the factory. IMR4895 and H4895 are made on opposite sides of the world by different processes.