If one assumes that temperature stability is related to cartridge size (charge weight) which powder(s) show the best range of stability from moderate temps (50-70) down to below freezing in the 338WM? Curious...

For the 210 grain bullets use;
IMR 4451 OR 4955

For the 225 grain bullets use:
IMR 4451 or 4955

For the 250 grain bullets use
IMR 4451 or 4955 or 7977

All are temp insensitive.

I've used Hodgdon Extreme Powders since I had an odd situation come up one year with R19/185 XLC load. I've tested R15 in my old 35 WAI and it is excellent "in that case size", if that means anything. I like to hunt late season ( late Dec-early Feb) cow elk and sometimes it can get pretty cold...others, not too bad. Just wondering about some of the older powders?

Has anyone ever had an issue with R19 in the 338WM in really cold temps, say sub freezing, losing speed?

I don't recall the cartridge, but on this very site I've seen some discussions about RL19 being one of the more sensitive powders.

Yes. I have seen variations at low and high temps with 19 and 17...I don't remember exactly how much variation but it was enough for me to change to H4350. With temps over 70 I saw some pressure signs with loads at the top end.

If you'll do a 'search' in the Reloading board you should find some old posts of mine on this subject. I chrono'd several powders in summer temperatures in California then ran them over the same chronograph in Wyoming and Montana in sub freezing temps. The powders with which I stayed were H4350, H4831 and N160. My favorite powders were RL22 and some RL19 but the difference in velocity was over 300 fps. In fact they shot pretty much the same groups even at the lower velocities and I took elk in each case but don't recall distance but for one that dropped at about 150 yards.

Thanks guys, I'm still researching some things out. My situation was a compressed load ( which turned into a solid cake) in addition to the cold temps. Loss of a bit over 200fps and groups opened to +-5". 10 days before the hunt put me into a tizzie, ha. I just went straight to H4350, worked up a load and went and killed my elk. But I've only used R19 again in '06 size cases, for example in two 240 Weatherbys. Its great in that case, at least it is to my observations.

This little fella took a 210 Partition over a bunch of RL19 right at 400 yards. Not saying it isn’t a problem but developing the load in 50 degree’ish temps and sacking the bull in 20’ish temps didn’t seem to matter much. My 338 has been pretty great with RL19 over the years and upon chrono work back home at nearly the same temps lost about 50 FPS, but that was back before the Magnetospeed as well.

I know temp sensitive matters at extreme range but for me, so far I haven’t had a problem.

Sometimes it isn't additional drop due to lower velocity that's the problem. Instead it's a largish POI shift in a direction other than vertical.

beretz,

50's to 20's usually doesn't result in more than 25 fps difference with any modern powder. In fact, usually 70's to 20's doesn't.

The critical temperature is around zero and below. This still MAY not make any difference at 400 yards, even if the velocity loss is 100+ fps, as long as the POI remains the same at 100 yards, as mathman pointed out.

Have tested many loads at 70 and zero. Usually there's no difference in 100-yard POI, even if the muzzle velocity's a lot slower at zero--but sometimes there is. I've seen as much as a 3" shift at 100, and it can be in any direction. That's unusual, but 2" is common with powders that lose considerable velocity in cold.

A lot depends on the rifle. Slimmer barrels usually show more POI shift, just as they do when working up loads, though sometimes they don't. But you never know unless you test 'em.

One thing I can say is that in 25 years of doing 70/zero tests with the same rifle and load, I've yet to see a significant difference in 100-yard POI with any load that varies 30 fps or less at those temperatures. And I've yet to chronograph any loads using Hodgdon Extremes that varied that much, regardless of the cartridge and bullet weight.

Many powders will do pretty well in certain cartridge/bullet combinations, but not other combinations. But again, you never know until you test 'em.

There's an article coming up on this in HANDLOADER that contains far more details, including a bunch of chronograph results for cartridges from the .17 Hornet to .375 H&H.

I'd try H4350 for starters. Generally I work up loads for my 338wm when it's cold, so the powder I use isn't as critical because that's when I hunt with the 338. I've had good luck with IMR 4350 as well, but I get a wider velocity swing with that powder vs. H4350. I've tried RL19 back in the 90's as well, but always fell back on 4350 of some sort in the 338...

I'm using r19 exclusively and shoot in temps between -20 or -30 to 75-80f. Not exaggerating...i shoot year round. I also use non-magnum primers as I find them more accurate. No issues here with grouping...though I don't chronograph each string.

My workup was in 60ish temps but I've not had pressure issues in hot weather nor ignition or group shifting in the bitter cold.

Keep in mind gents im talking punching paper at 100m

EXACTLY my results as well. When I shifted from 215s to 210s, groups shrank considerably.

Thanks guys, I played some with R26 and R33 in my last 7mm Rem Mag. Anyone tested R26 in real cold and/or R17? I am particularly interested in how they do in the 7x57 and the 338WM. If they aren't pretty stable, I'll skip over them in load workup and stick with Extreme powders.....old dogs/new tricks kinda thing, ha.

I'm using H 4831 SC with the 250gr Accubond with my 338 Win Mag. I found it to be the most accurate in my rifle. Also in my part of B.C one week it can be 10 above next week -10. So the extreme powder actually makes some sense.

Testing @ 70 down to zero or below, do you think the POI shift is more often temp sensitivity of the powder or something being wonky with the rifle? Just wondering what your opinion is regarding POI shift, is it more often the rifle itself or the arm?

It's not something "wonky" with the rifle, but it is a combination of both velocity loss and the rifle.

Anybody who's worked up handloads should have observed that various powder charges, even with the same powder and bullet, do not always shoot to the same point of impact at 100 yards. This tendency is greater in lighter-contour barrels, especially when free-floated, but can occur even in heavy barrels, though the differences in POI won't be as large. This is because different powder charges change the vibrations of the barrel slightly--which is also why we try different powder charges, to find the charge that results in the smallest groups.

What I've noticed over the past 25 years of testing the same handloads at 70 and then again at zero is that rifles which show a noticeable (say an inch or more) POI shift at zero degrees are normally the same rifles that show larger differences in POI when trying handloads with different powder charges. In other words, if when trying various 165-grain loads with your .30-06, ammo with powder charges of 55, 56 and 57 grains of IMR4350 land in noticeably different places on the target, then that rifle is also likely to shoot the SAME load of IMR4350 to different places at 70 and zero degrees. While IMR4350 isn't as temperature-sensitive as some other powders, it does tend to lose velocity from 70 to zero degrees.

Exactly how much depends on the specific cartridge and load, but I've seen IMR4350 lose anything up to 75 fps from 70 to zero. This may not seem like much, but in that instance POI at 100 yards changed two inches--and upward. Loss of velocity does NOT always mean a lower POI at 100 yards, any more than higher velocity always causes a rise in POI when working up handloads. It all depends on barrel vibrations. (Have also seen IMR4350 lose only 35 fps from 70 to zero, in a different cartridge, with no change in 100-yard POI. As I've noted before, much depends on the specific load and rifle.)

Other odd things can happen. One of the very first cold-temperature tests I made was with a very accurate .270 Winchester, using both the original military-surplus H4831, and Reloder 22, then a relatively new powder. Like many .270's, this one tended to put 130 and 150-grain loads into the same place at 100 yards, and the most accurate 130-grain load used H4831, and the most accurate 150-grain RL-22. But something weird happened while hunting in very cold weather with the 150-grain load, so afterward I tested it on a cold morning, also trying the 130-grain load as long as I was out there.

Both loads lost well over 100 fps, the H4831 load 151 fps and the RL-22 load 129 fps. (Remember, this was the original WWII era H4831, not today's Extreme H4831, a totally different powder.) The RL-22/150 load shifted its POI 3 inches to the right, the reason for the weird result while out hunting. (I probably don't need to remind anybody of this, but a 3-inch change in POI at 100 results in a 6-inch change at 200 and 9-inch change at 300--NOT 3 inches at all ranges.) The 130/H4831 load did NOT change POI, but went from 3-shot accuracy under 3/4" at 70 degrees to nearly 2-inch groups at zero.

As I noted earlier in this thread, there's a long article on this subject about to appear in HANDLOADER. No doubt many people won't read it, because they don't want to pay money for information when there's so much free information on the Internet, especially from notable Campfire members like Savage 99, but also because their attentions spans are too short.

But perhaps the two major points in the article are that I've yet to see any noticeable change in POI at 100 yards with powders that don't vary more than 30 fps in velocity from 70 to zero, and that with powders that aren't temp-resistant, you never know until you test 'em at widely different temperatures. More often than not there isn't any difference in 100-yard POI, but when there is it can be significant.

Today I sent some 225 Nosler Accubonds down a Ruger 77 at 2,950 burning 75.0 of RL23.

No signs of pressure



Win brass
CCI Mag primer

Awesome post John. I've seen a lot of the same velocity loss while using IMR 4350 powder and the 30-06 with 165's. The rest of your post also reflects the same things I've seen over the years.

That's a good load SU. I don't run my 338 that hot, here's about what I get in cold weather:

Averages around 2,860 fps, but damn accurate....

I do like the Hodgdon H4350 powder in the 338 for sure. I haven't been able to locate any RL23 around here, or I may think about trying it in my old rifle....:

That kind of accuracy is great! good for you.

No way of knowing target accuracy for RL23 as right now as I'm using NECG open sights on the Ruger, no scope.

I’d like to see how RL16 runs. Seems very 4350 like in speeds and such and is touted to be pretty stable. I’m looking forward to working with it more in the future. Some of my first loads with 180 Accubonds and the 30-06 looked promising. I sorta got tired waiting on H4350.

Great points by all of ya, thank you.

I gave up on "waiting for H4350," partly because as I get, ah, more mature I'm not as willing to continually search for scare components or ammo, which is about the only way to find them. And even when you find some, if it's something you use a lot (whether H4350 or .17 Mach 2 ammo) then it's only a relatively short while until you're looking again.

Which is why I quit shooting ground squirrels with my CZ .17 M2 and sold it, along with what ammo I had left, and why I started trying substitutes for H4350. Right now the leader is IMR4451, partly because it's so similar to H4350 the data is almost interchangeable. In fact Hodgdon's on-line data lists the maximum loads for 225-grain bullets in the .338 as 69.5 grains for H4350 and 69.4 for IMR4451, with an 8 fps difference in muzzle velocity. Have also thoroughly tested IMR4451 in cold temperatures and it's just as stable as H4350, but contains a decoppering agent, which is nice for extended shooting sessions. So far it's been H4350's equal in every load tried. The only occasions when there's been a difference in accuracy, 4451 has been slightly more accurate.

Started using RL-23 just last year, but so far am impressed as well. It's not quite as available as IMR4451, but far more so than H4350. Finally found some RL-16 this summer, but have only tried it in one cartridge so far, the 6.5 Creedmoor. It gets great velocity but so far accuracy hasn't been as good as with 4451.

I'll have to check the availability of IMR4451. I've been lucky over the past 3 months and found 6 pounds of H4350, but like others have said it's damn hard to find. If there's a powder out there that's just as good and a lot easier to find, I'm going to be all over that. Like beretzs said, good info here... Thanks

bsa,

Except for maybe 2-3 months earlier this year, after all the new 6.5 Creedmoor shooters "discovered" 4451, it's been very available. Some people like to buy in local stores, instead of off the Internet, and I see it frequently the half-dozen local stores I visit.

But I mostly buy 8-pounders off the Internet, and even during the brief break in availability earlier this year my supply never dropped to the point it has with H4350. I was down to maybe 10 pounds before ordering some more a couple months ago, and these days I use 4451 in just about all the cartridges where I used to use H4350, and continually experiment with it in more, partly for articles and partly for my own use. So I'm using a LOT.

Do still have a few pounds of H4350, but about the only reason I keep some on hand anymore is to include it in articles about handloading a certain cartridge, for the readers who still have some, or are still desperately searching. I'm outta that game.

Thanks JB. That 4451 looks very promising. I'm going to be on the look out for some locally.

I bet you like it. If you decide you do and want more, Internet ordering 8-pounders usually results in prices at least as good as brick-and-mortar stores, even with the hazmat fee--which many have been reducing or even eliminating lately, at least temporarily.

I just checked the five websites where I order most reloading stuff. None had H4350, but only one didn't have IMR4451.

John- is R23 a "sort of" replacement for R22, only more temp stable? How does it com[pare to R22?

The burn-rate is similar, but not exactly the same. Like all powders, burn-rate will vary slightly with specific loads.

In my limited temp-tests so far it's been very good. Last I tested a bunch of powders and bullets in my special-run Tikka Superlite .260 Remington from Whittaker Guns, and the all-around winner (for my purposes anyway) was the 140 Nosler Accubond with a max load of RL-23. Very similar results from 70 to zero, both in accuracy and velocity (in fact it was a little faster at zero) and of course it worked very well in the field.

John, how does the 4451 compare to IMR 4350?

In most cartridges the load data is very close, if not identical. Of course, both will vary slightly from lot to lot, but so far the 4451 loads I've ended up with are no more than half a grain different than the H4350 loads in the same rifle with the same bullet, case and primer.

That's interesting MD.

Should have mentioned that over the years I've found H4350 and IMR4350 to produce very similar results--but again, IMR4350 can vary from lot to lot.

In other words, there's a LOT of overlap between all three powders.

Thanks, I just picked up a LB of R23 and another LB of H4831sc Saturday. I have shot a lot of R22 from magnums down to the .224 TTH and only had a slight issue at warmer temps, none at colder ( that I could tell, of course :))

To those interested.

Nosler 180 AB
IMR 4451 76.0 grains 3,205

Nosler 200 AB
RL 23 75.0 grains 2,996 mv

Nosler 225 AB
RL 26 76.0 grains 2,824 mv

Nosler 250 Partition
RL 22 75.0 2,830 mv

Nosler 250 Partition
RL 23 75.0 2,726 mv

Sounds pretty damn good to me. Now I just need to find some of that stuff!!!!

Checked my notes and I'm getting 2850 on the nose with 73.5gr of R19 with a cci200 from my 26 inch Winchester 70 at 61 degrees. Easy on brass

Great info! That’s about what I saw with 26. It was really good with 250’s.