IMR 4166

Wendyj

New member
This powder keeps popping up in magazines and people at my range. It shows it helping keep barrel cleaner and supposedly does well in 308 based cartridges. I bought a lb today to experiment with. Anyone use this in 260 or 308? Wanting to try it out in my 260 with some Sierra Match Kings. According to chart just a tad faster than IMR 4064. It seems very plentiful around here.
 
Hi. Stuff's only been on the market since last October. Hard to tell if Hodgdon's claims about copper fouling are true.
 
Yes, thank you. I usually put around 10 Barnes along with a bunch of 140 gr smk every range session. The copper fouling really sucks to clean. Doesn't fill case to much capacity with me backing off to 33 grains. 44.5 max according to Hodgdon. That's not a Barnes load. Not a lot of load information for it. 260 shoots best around 24-2500 fps with any bullet I've found. That seems to match speed from Nosler but won't know until I chrono.
 
"...44.5 max according to Hodgdon..." That supposed to be 34.5?
Don't load .260 myself. My 90 grain .243 ground hog fightin' ammo likes IMR4350. Uses a bit more powder for 1 fps less velocity. Pressures are in CUP for the 4350 vs the PSI for the 4166.
You using a Barnes manual? Their site is decidedly limited.
 
That a typo on my part. iPad keys too small for even little fingers. Yes, I have a Barnes manual. No, this powder isn't even listed for the 129 lxr. Bullet was new enough I had to call Barnes for load data. Been using H4350 and IMR 4350 and the Hodgdon wins for accuracy at 41 grains seated at 2.750. I tried a little longer but these things like a jump in my Tikka. They listed Hybrid 100 V as most accurate powder.
Hodgdon lists 31.7 to 34.5 for the IMR 4166. That's for a Nosler partition 140 grain but I mainly shoot 140 smk and 129 Hornady sst out of mine. The Barnes are tack drivers out to 500 yards but I've got a lot of work to do to push them any farther with accuracy. At 600 they open up like shotgun rounds.
 
Hi. Full size PC key boards aren't any better. They're not made for adult fingers. Have to proofread everything. snicker.
The maker of the bullet doesn't matter. Only the weight matters. So the load for a Nosler 140 will be the same as a 140 Match King. Pretty much the same price for the bullets too. Nosler stuff is horrendously expensive
I've been wondering if the 4166 is 4064 with the addition of the copper fighting chemical. Velocities etc are really close.
 
I should preview mine but sometimes get in a hurry. Burn rate chart shows 4166 as number 94 and 4064 is number 95. They can't be too much difference. You can see the large flakes like 4064 has and a much smaller flake of a different color I'm guessing is the cleaning agent. I am going on call Friday and won't get to shoot until next weekend. I'm curious of what chron readings are going to be. I'll post back when I get a chance to try some in the 260 and 308.
 
Hi. It's hard to compare 'em as Hodgdon gives 4064 pressures in CUP and 4166 in PSI for the .243 data. There is no converting that one to the other either. I'm just thinking velocities with a given load. Mind you, their .260 data shows slightly less powder gives slightly less speed, but more pressure with the 4166. Don't think it makes much difference.
 
T O'Heir, I'm pretty sure that while bullet weights matter a great deal in terms of powder charge, so too does bearing surface. Unless I really missed the mark here, the Barnes pure copper slugs are significantly longer, with longer bearing surfaces, than traditional lead core, gilding metal jacketed, bullets.

I'm not sure, but I recollect that the Barnes bullets do require a lighter load to achieve similar pressures.
 
T O'Heir, I'm pretty sure that while bullet weights matter a great deal in terms of powder charge, so too does bearing surface. Unless I really missed the mark here, the Barnes pure copper slugs are significantly longer, with longer bearing surfaces, than traditional lead core, gilding metal jacketed, bullets.



I'm not sure, but I recollect that the Barnes bullets do require a lighter load to achieve similar pressures.


This makes more sense than all bullets give the same pressure with the same load. Could cause trouble if you don't pay attention to the details.
 
The Barnes bullets are a different animal of their own. I had to contact Barnes for load data and seating depth on the 127 grain lxr. It has its own powder of H4350 at 41 grains. Seated 2.750. I stretched a few out to 2.80 and group size changed considerably. They will hold .35 at a hundred with their specs. That's about 2500 fps on the chronograph. The IMR 4166 seems to have better powder charges for the .308. I picked up some IMR 4451 which is supposed to be closer to my 260 loads. Can't do much more than experiment with both and ladder up until I see pressure signs. Both powders are getting really good reviews but of course my loading manuals don't show these powders. Hodgdon does have loads in their manual for them so I'm just going with their mid range loads to start. I have a muzzle brake on the 260 and the 308 and haven't loaded any of these in 308 yet but muzzle flash in 260 is almost nonexistent. I'll be loading this week and shooting next weekend.
 
Not talking about the bullet at all. Just the powders.
"...Barnes bullets are a different animal of their own..." Hi. Yep. Been saying that for years now. And getting all kinds of daft comments from others. Some don't seem to get it that a solid copper bullet is less dense than a lead cored bullet. Mentioned that a solid copper flies differently than a lead cored on another forum and got an excrement storm of FNG's whining about it.
I kind of suspect Hodgdon may have invented their CFE powder line specifically for solids. Don't know for sure.
 
Hodgdon didn't develop the CFE line, General Dynamic did for military reasons. Newer lead free projectiles were causing excess copper fouling the older FMJ with exposed lead base didn't.

Barnes bullets had nothing to do with it, people just aren't running those solids through their hunting barrels the same way a military machinegun is pushing through ammo.

But, for a lot of folks it's a dang good improvement that helps with barrel maintenance.

Jimro
 
Hi, Jimro. Excellent info. Always laughed when in the CF, long ago. The only thing we got for cleaning everything from .22's to at least .50 BMG's was regular motor oil. Forget if it was 5w or 10w. Wasn't a drop of any kind of solvent in the entire CF supply system.
 
Motor oil is great for carbon fouling. I used it, and ATF, a lot on machine guns.

It's always funny how some military veterans swore by "Breakfree" because they used it all those years cleaning everything from M16s to M2s.

The exposed lead base of the bullet really helps reduce copper fouling, atomized lead mixes with hot copper to form a highly brittle amalgamate which doesn't stick to the bore.

Then they get a hunting rifle, or join a military rifle team, and start shooting bullets with reverse drawn jackets which don't have exposed lead, and all of a sudden "Breakfree" doesn't work so well...

A couple years back I had a crazy idea to buy some micronized tin dioxide to mix in with my reloads so I wouldn't have to buy new CFE powders... But I never got around to it, or trying the cheaper version and just adding a small sliver of lead or solder compound to the mix. They used to do that with artillery shells, putting elemental lead inside the shell to decopper the tube...

Jimro
 
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