IMR Enduron Powders

[mwkelso]

One of my local suppliers has been getting these in pretty consistently through the shortage of the H1000, N570, Retumbo, etc.

What has your guys' experience been with these powders?

They would be used mainly for the 300wm pushing either 190ablr or 200 accubonds, paired with CCI250's in Gunwerks brass.

Might consider running it in the .270 if I run out of H4831 and can't get it again. 140 TSX or 140 Accubonds, CCI200 and RP brass their.

Thanks!

 

[Trnelson]

I have been using 4166 for 185g loads in my 308. I have zero complaints. SD has been very consistently 4-6fps. I've shot it from 0• up to 82• and had exceedingly minimal shifts in velocity. The lack of copper fouling has been a treat. 7977 is most likely the burn rate that you will want to work with, it is most similar to H1000.

 

[Doublezranch]

This thread seems to have some real life experiences.

IMR Enduron Powders

Has anyone had much luck with the enduron powders? I picked some 4166, 4451 and 4955 up. The plan is to play with them and see what I can do with them with the 22-250, 7-08 and 7 mag and some Barnes bullets.

www.longrangehunting.com

 

[243winxb]

I am trying out 4166/223 Rem/69 gr & 4451/243 Win./90gr. They seem to work as well as other IMR powders. 4198, 4350, 4831. More shooting is needed.

The big difference is the Enduron Powders are double based , containing nitroglycerin.

Great bullets, are more important.

 

[Hugnot]

I have started using IMR7977 in the 6.5-06 with 130 H ELDM's & 130 Nosler RDF's. No chrony data yet, loaded at 55.0 grains for both 130 grain bullets. Pressures appeared to be mild normal. Bad day for shooting with gusty 15-17 mph wind but was able to get sort of a good 5 shot group between gusts of about .75 inches at 100. I used CCI 200 primers and carefully prepped Win .30-06 brass.

Plan is to gradually increase powder charges by .5 grains and deploy chrony. Also plan to load some 140 Hornady hpbt's & Barnes 140 MB bullets with IMR 7977.

The powder is dark gray, almost black, of medium grain size, .070 x .038, with tiny hole in middle of cylinder, grains appear to be uniform. 7977 has greater density than RL23, same volume of RL23 weighs 52.4 grains vs. same volume of IMR7977 weighing 55.5 grains (can get more in case). 7977 does not flow as smoothly thru powder measure (sticky) as RL23 despite grain sizes being about equal and weighing more.

Having greater density than other comparable slow burning powders might make 7977 a good powder for .243W with 105's & 107's like compared to H1000.

Enduron powders are claimed to reduce copper fouling. Some unknown additive is included in the Enduron powders to reduce fouling but is not named anywhere. Other powders that claim to reduce copper fouling contain tin, no mention of tin in the Enduron MSDS info.

 

[Dosh]

Like the Hodgdon Extreme powders the Enduron line is temp stable. I have a couple pounds of all five of them. Bought them cheap. Good to have for substitutions. I loaded 8133 to test in my 30/378 and it was a lot more potent than the load data stated, start minimum and work up.

 

[mwkelso]

I have started using IMR7977 in the 6.5-06 with 130 H ELDM's & 130 Nosler RDF's. No chrony data yet, loaded at 55.0 grains for both 130 grain bullets. Pressures appeared to be mild normal. Bad day for shooting with gusty 15-17 mph wind but was able to get sort of a good 5 shot group between gusts of about .75 inches at 100. I used CCI 200 primers and carefully prepped Win .30-06 brass.

Plan is to gradually increase powder charges by .5 grains and deploy chrony. Also plan to load some 140 Hornady hpbt's & Barnes 140 MB bullets with IMR 7977.

The powder is dark gray, almost black, of medium grain size, .070 x .038, with tiny hole in middle of cylinder, grains appear to be uniform. 7977 has greater density than RL23, same volume of RL23 weighs 52.4 grains vs. same volume of IMR7977 weighing 55.5 grains (can get more in case). 7977 does not flow as smoothly thru powder measure (sticky) as RL23 despite grain sizes being about equal and weighing more.

Having greater density than other comparable slow burning powders might make 7977 a good powder for .243W with 105's & 107's like compared to H1000.

Enduron powders are claimed to reduce copper fouling. Some unknown additive is included in the Enduron powders to reduce fouling but is not named anywhere. Other powders that claim to reduce copper fouling contain tin, no mention of tin in the Enduron MSDS info.

This is good to know, thank you!
I have used RL23 many times before and had wished it was a higher density in all of the 30-06 type cases. Magnum cases it usually wasn't a deal breaker...

 

[243winxb]

Not a lot available now. https://ammoseek.com/reloading/powder/IMR?ikw=enduron

 

[crazyhorse]

I've used three different versions of the Enduron series (not at home to be sure of which but I know 8133 is one of them) and without a long hair splitting conversation, I've found them to be very stable and as good as the others with proper load work up.

The only big difference I noticed is fouling. Its true that you get very little copper left behind but cleaning out all the carbon requires more than most other powders I've used.

 

[vancewalker007]

One of my local suppliers has been getting these in pretty consistently through the shortage of the H1000, N570, Retumbo, etc.

What has your guys' experience been with these powders?

They would be used mainly for the 300wm pushing either 190ablr or 200 accubonds, paired with CCI250's in Gunwerks brass.

Might consider running it in the .270 if I run out of H4831 and can't get it again. 140 TSX or 140 Accubonds, CCI200 and RP brass their.

Thanks!

I've been using 7977 for years in the 2 7mm LRMs I load for. It builds up very little copper fouling and produces fine accuracy, 1/2 to Sub 1/2 MOA. We used it last year behind a 180 VLD to kill an Elk at 1092yards. Because powders can go in and out of stock I always have a 2 loads developed for each rifle using 2 different powders. In the case of 7977 it's a backup to H1000 and H1000 is a backup to it. They have very similar burn rates. It also shot great in my 6.5 PRC.

I don't know how it will work in a 300 Win but 4451 works great in my old 300 WSM and my 375 Ruger. It's similar to 4350.

I recently tried 8133 in my 6.5 PRC. It shoots really great but it's slower velocity wise since it's a slower burn like Retumbo.

 

[rbTanzan]

I have been using 4166 for 185g loads in my 308. I have zero complaints. SD has been very consistently 4-6fps. I've shot it from 0• up to 82• and had exceedingly minimal shifts in velocity. The lack of copper fouling has been a treat.

Do you have any recipes for 308. It would be good to hear the 185gn load and I would especially like to hear of 150-152 and 168gnTTSX loads.

Thanks.