Home Forums Hunting & Shooting Savage Collectors IMR 4166 in the .300

I dug up only one thread in this forum containing some data from mathman regarding this powder in the .300 Savage, figured I'd add my findings.

I no longer own a 99 in .300, and this work was done for an Interarms Mark X which would handle higher pressure rounds without issue. Like mathman I found 39 grains a good starting point and it averaged 2506fps with a 155gr Hornady A-Max. Primers looked good, had easy bolt lift and extraction. My club held a long range silhouette match today and that one doped out well for turkeys and rams.

Also tried this powder with 125gr Speer TNT varmint bullets, but the loading I'd done using H4895 with that one for my 99R was good in the bolt gun as well. Same with Reloder 7 and Sierra's 125gr Pro Hunter, Chicken and pig loads.

I've shot a number of factory rounds through both of these rifles, not at the same time so no true direct comparison here, but my chronograph saw:

Remington 150gr Core Lokt 2530fps in the 99R, shot them all up prior to building the Mark X
Federal 150gr SP 2655fps in the 99R, 2660fps in the Mark X
Winchester Power Pt 150gr 2592fps in the 99R, 2704fps in the Mark X
Hornady Superformance 150gr, bought after selling the 99R, 2695fps in the Mark X.

Have to shoot more of the Winchester ammo through the bolt gun. Just in case it repeats.

Would like to see one of the bullet companies work with this powder in the .300 to get good known, safe loads for 99s, I've also done some shooting with this and IMR 4451 in a .250 AI bolt action rifle, but a Sierra tech tells me they have no intention of working further with that cartridge. My rifle follows very closely with the data they published for the cartridge.

I'm happy with H4895 and Reloder 15 in the .300, was curious what the newer powder might provide. Limited trial with the RL15 round that worked so well in my 99R didn't look so promising in the bolt but I've got some leeway with seating depth as that one's only 2.56" oal with throat room in the bolt. That, and a little more or less powder, should get it right.

For reference, here's the prior thread https://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/11963946/1

I'd be interested inaccuracy. I don't think greater velocity is a thing worth chasing in the .300 anymore.

Probably true. My work with 4166 peaked at 2779fps with the Speer 150gr Grand Slam but even 100fps over factory loadings is pretty meaningless. I think accuracy translates even worse between guns than velocity, would like to have tried the 2500fps A-MAX load in that 99R though.

The claimed temperature indifference and copper fouling removal of the new powders is interesting, I'll probably try CFE223 with the lighter bullets since that one works in other calibers for me. Part of the reason I buy different calibers, or something else in a caliber already owned, is to see what I can assemble for it.

Sounds like a worthy pursuit to me. I'm not familiar with the powder so I find your comments interesting. Please post on any further results with 4166.

I have a pound of 4166, but have yet to load any ammo with it. My go-to powder in the 300 Savage is WW-748. 41 grains of the stuff under a 180 grain round nose bullet gives 2,450 in a 24" Model EG I own. In shorter barrels, velocity is less, about 2,350 in my 99 E with 20" carbine barrel. I have fooled around with Leverevolution (LVR) powder a bit. I broke down a factory round of Hornady Superformance ammo to find 44.5 grains of a powder looking like LVR. It chronographed 2,700 fps in my 99 F with 22" barrel, and 2,600 fps in the 99 E. Accuracy was nothing to write home about. I tried handloads, and results were about the same as factory ammo.

I have found the Ken Waters Pet Loads to work well. They are the above 180 grain load, and two 150 grain loads: 40 grains of IMR 4064, and 42 grains of WW 748. Velocities are not stellar, but accuracy generally is.

My current effort is using LVR powder with 180 grain bullets, hoping for a meaningful increase in velocity over factory loads (about 2,375 fps). I'm probably chasing my tail.

Ken Waters Pet Loads is a great go to manual for reloading. Nobody will come close to his published work in handloading and I too have found his loads to work. Waters usually was straight forward in stating that the most accurate loads were not the highest velocity loads.

kgb41,

Haven't used 4166 in the .300 Savage but have worked with it extensively in eight other cartridges from the .204 Ruger to the .45-70. Like many newer powders, it has several small advantages over older powders. Most handloaders (especially deer hunters) don't see these advantages because their experiences, and needs, are pretty limited.

Aside from being clean-burning, it's very temperature resistant and contains a decoppering agent. The temp-resistance is helpful for some hunters and not for others, but at typical .300 Savage ranges usually isn't a big deal--though contrary to what many hunters believe, the big disadvantage of more temp-sensitive powders isn't lost velocity in cold weather, but potential changes in point of impact at 100 yards. I've seen as much as three inches change from 70 to zero degrees Fahrenheit, which doesn't matter in deer hunting if you only shoot at relatively close ranges but could beyond 100 yards.

It's a "short-cut" extruded powder, resulting in more accurate metering through a mechanical measure, but the granules aren't noticeably different in size from IMR4895. However, 4166 is double-based, resulting in more energy than single-based powders like IMR4895 and Varget, so somewhat more velocity can be attained, though as you noted in the .300 that's pretty meaningless. So is the decoppering agent, since .300's usually aren't used for extended shooting sessions.

I also found 4166 very accurate in all the cartridges I tried it in, and in fact turned out to be the most accurate powder I've ever tried for certain bullet weights in a couple of cartridges. But again, how much does a little more accuracy matter in a modest-velocity big game round typically used at "normal" hunting ranges?

Such incremental advances have been occurring ever since the development of practical smokeless rifle powders in the 1880's. The earliest smokeless powders were so temperature-sensitive they often locked up actions in warm weather, and wouldn't always go bang in cold, and fouled barrels in a number of interesting ways. Early British Cordite was so sensitive ammo companies often offered two loads, one for cool weather and one for the tropics.

After that powders improved so rapidly that many shooters decided they were were perfect by the 1930's, when Dupont introduced most of their IMR powders--though many had faults, including large granules, and were still somewhat temperature sensitive, though many hunters don't shoot in conditions where it's obvious.

Eventually we'll probably end up with powders that provide exactly the same velocities at -20 and 100 degrees (so far none I've tested have), and do not leave any copper or powder residue in the bore, making barrel cleaning obsolete.

To most deer hunters the latest advances don't mean much, but they're there for shooters who can use them.

In my .204 Ruger IMR 4166 did a fine job with Berger's 35gr bullet, CFE223 did better with some others, and at least has the decoppering element,but H4895 and RL15 also had great combinations. The rest of my bottleneck centerfire rifles are pretty much interchangeable, 6mm Rem, 250Imp, .270 Win and this .300 are probably equals for deer the way I hunt them. The 6mm's a 788 that now wears a #5 contour Shilen bbl in place of the original so weight takes it out of the deer picture, IMR 4551 made up a good version of the load I used in the original barrel with an 80gr Blitz, hopefully it or 4166 will do likewise for an 87gr V-max. For such rounds a powder to keep velocities relatively constant under varying weather will be appreciated.

The other deer calibers can likely continue using what has worked for them in their use, the silhouette shoots have been summer events but I'll pay more attention to velocities in say 70deg vs. 90deg+ conditions. Should be easy to work up something for each in their given bullet weights with these two Enduron selections, if current favorite with other powders show sensitive to cold. I don't think I'll ever shoot anything to equal the rate of fire in the silhouette matches with these bigger calibers,

One thing that's been consistent from hot to mild wx, admittedly not checked in the cold, is a favorite load for the Speer TNT in the .250AI. That one uses WW760 and always shoots fine groups with consistent velocity. I'd be happy to construct a cold weather variation if needed, won't give up the 760 though.

A friend who worked a rod and gun club in Spain in the 80s told me they got their shotshells through a local distributor and they appeared to change the recipe as the weather changed. Shells purchased in the winter gave noticeably increased recoil if kept through to hot weather and fired then, and the supplier told him they were loaded with a powder called Santa Barbara, available for reloading as well. This was a flake powder that looked like Unique, apparently considered sensitive enough to temperatures that the producer altered the charges to compensate. Might be true.

I might try these new powders after I make it through the stocks of powder, which may take 20 years I have so much. Still PO'ed that they discontinued SR-4759, but I do have about 16 pounds of it.

I didn't wait, and now that I've finally emptied the last 1lb can of H4895 in the house it's time to open the 8lb-er of it. That one will probably go 20 years, but I'm looking forward to it