IMR Enduron 4166 is a versatile, match-grade propellant, with the fastest burn rate in the Enduron line. It is an extruded powder with a perfect burn speed for cartridges like 308 Winchester, 7.62mm NATO, 22-250 Remington or 257 Roberts, among other cartridges.
The main features of the Enduron series are copper fouling eliminator, insensitivity to temperature changes, ideal loading density and being environmentally friendly.
This propellant performs comparably to Hodgdon Varget but charge weights are materially different.
IMR recommends always consulting www.IMRReloading.com for the most accurate, up-to-date data.
Available in 1-LB and 8-LB containers.
Posted by Paul on Aug 25th 2022
very consistent in .243 shooting 65gr vmax and 3550 fps. temperature stable too. worst groups at .5 moa most groups around the .3 moa mark.
Posted by Jeff Kuhn on Jun 28th 2022
Varget was always my go-to powder for .308 and .223, but anyone who reloads knows that Varget is virtually unobtainable now. I have enough on hand to last for a while, but when I found some IMR 4166 available, I decided to try it for my MPA .308. I did the usual load development testing and found that 43.0 gr. of 4166 in Peterson SRP brass topped with 168 gr SMK's seated 0.010" off gave me great performance. At 600 yds, the POI with 4166 loads was about 1.2 MOA higher than when using 43.2 gr. of Varget. I shot a 4.125", 10-shot group at 600 yds - well under 1 MOA and slightly better than my Varget loads, although they were close enough that I attribute the difference to the shooter. I was planning to switch to 4166 for my .308, but it seems that it has also become nearly impossible to source. It's been over two years of this ammo & reloading nightmare. We need to get back to the good old days! Anyway, I like the 4166!
imr4166 is great in 6mm dasher
Posted by Christopher Brown on Apr 19th 2022
I use this powder in my 6mm dasher bench gun. the accuracy is the same as varget but the velocity is a bit higher with a couple of 10ths less powder. this stuff is not affected temp at all. I live in florida and shoot the same load all year. Great stuff!
Posted by Randy on Nov 26th 2021
Really like this powder, the accuracy it produces is amazing I will lots more if I can find it. Love the copper fouling eliminator makes cleaning a breeze
Very consistent velocity
Posted by Paul rosenkranz on Nov 9th 2021
Very consistent velocity, quality powder, not so good on powder throw due to it being a stick powder. Other than that , great job, thanks.
4166 in my 223
Posted by TY on Oct 24th 2021
I'm using this in my Tikka CTR 223 under 73 gr Berger BT target bullets. Was able to find a node fairly quickly and with a little seating adjustment, it's shooting .3 moa or better. I'm very happy with this powder.
First 308 loads
Posted by Alexis Perez on Oct 13th 2021
Was looking for an equivalent powder from H4895 when I ran into the 4166. First load. CL 2.005 OAL 2770 Sierra Case 44gr 4166 5 rounds shot FPS low 2735 high 2789 My factory sierra high 2576... Awsome powder in my book.
Imr-4166 in 30-30 win.
Posted by Harper on Aug 30th 2021
Loads case to bottom of bullet, clean burning, very consistent, accurate results with no flyers, flows thru powder measure with a. .1 to .2 gr accuracy. Will purchase more. Thanks
Posted by Phillip Jackson on Aug 1st 2021
This is a great powder for my .308,.