Boy, this got my attention. I was shooting my son's Rem 700 CDL SF .257 WM at the range last Monday and brought along a half empty box of shells loaded with a max charge of R22 and 110 Acubonds. He and I had switched to H1000 and 100 gr TTSX's a year ago.

I finished shooting the TTSX' s with a max load of H1000 and grabbed the R22 Acubonds. I immediately had a sticky bolt. Hmmm. Should have stopped there but I didn't. A couple more shots and it went from a sticky bolt to a hard to lift bolt. Done shooting that load right then and there.

The temperature was around 95 degrees. Never had an issue with that load before BUT we never shot it when it was that hot. If I use R22 again it won't be at a max charge.

You are in good company. I learned the same about 25 years ago. My 7mm RM max load of R22 blew a few primers on a hot August day at the range before hunting season. I decreased the charge and all was well until late Elk season on a cold snowy day my shot hit a foot lower than my aimpoint. The cow dropped to her knees for a minute then got up. I didn't fire a second shot because I was so sure of where I thought I hit her. She took off with the herd and the tracking was on. Several hours and miles later I finished the job but I learned something. Temperature matters.

I shot RL-22 in my 280 Rem for years and would see a little variance during really hot weather, but since I don't hunt in hot weather it really was a mute point for me.

I moved on from RL-22 to IMR-7828 simply because I wanted to try it and I found a good deal on many pounds at a store that was getting out of the reloading business. I have found that this powder in my 280 is awesome with 154 gr SST's and 150 gr NBT's.

I went to the range today, it was 94 degrees and 93% humidity. This load shot same POA today as during cooler weather.

I quit using RL22 about 15 years ago for the same reason. I had my chronograph set up one hot Mississippi day and I watched my 7mm rem mag velocities climb from 3150 to 3415 shooting 140 gr ballistic tips over the course of about ten shots. I thought my chrono was lying to me until I started getting sticky bolt lift and ejector marks on the case head.

Do you mind listing the charge as I am reloading for the 257 Weatherby now. I have seen the maximum charge for R22 & MRP with a 100 grain bullet vary from 68 grains to 72.4 grains. Different cases and bullets but that is a fair amount of difference. What I have seen with R26 at least in one instance as a slightly under max load did not spike with 90 degree temperatures whereas another which may have been too hot to begin with went off the charts at 100 degrees, possibly hotter as the ammo was in the sun.

With other loads of R22 I have not seen a drastic difference but they have only been used from single digit temperatures to the mid 80's and probably were not max charges. But it varies by case, cartridge, and load.

When I re-stock on powders they will be R23, R16, H1000, 7977, 8133 and other more temperature stable powders.

I've used R22 in several cartridges since it came out. Never had an issue with it and still prefer it to many of the newer offerings that claim temp stability. I always do load work up in close to the same conditions/temps that I plan on hunting in so unexpected spikes never happen. Just this past fall I worked up a load for my 7 Mashburn using Retumbo to use on a NM elk hunt. Many range sessions in September had very consistent speeds so I loaded up a good supply. Back in January I took it to the range and my velocity dropped 60fps from where it’d been last fall! That showed me that even a supposedly temp stable powder isn’t always stable.

John55,

What kind of chronograph did you use to check the Retumbo load?

I discovered sticky bolts with RL22, so I finished my load development on hot days to insure my loads were not to hot.

Also a load that is ok in one rifle might be to hot in another. I always use the magnum primers in my loads to help cold weather ignition.

Not use it helps, but it never failed to go off. I have changed from RL22 to RL23, RL16, Retumbo, and H1000. I still use MRP where it will not get to cold.

yep RL.22 is a powder that has a problem in hot weather my 257 Weatherby mag. did the same stuff blown primers, sticky bolt so i only use RL.22 for hunting in the fall,temps are better then for RL.22 powder. but my Ruger #1 using RL. 22 never has a problem warm or cold,i still like RL.22 for this reason > i get very good groups and lots of speed out of a Nosler Partition with RL.22 3800 fps.

100 gr partition? 3800 fps? I wouldn't touch that load with a long stick.

my Ruger #1 has a 27 inch barrel , #1`s have a very strong action compared to most bolt actions. i know of a ammo manufacture who uses Ruger # 1 actions to test their ammo,there are many other 257 Weatherby Mag. handloaders shooting that same speed with 100 gr, bullets too. you smack a big buck with my load at 100 -200 -300 yards its a no track`em load > Speed Kills.

John, I used a Lab radar. Checked the loads on more than one occasion and they were consistently over 60fps slower than in early fall. Also tried them thru the CED Millenium with same results.

The R22 load? 110 Accubonds over 69.5 grs of R22. Fed GM 215M primers and Norma brass. I am done with R22 after that episode.

How many grains of R22 are you using?

I carry my rifles, all of them at one time or another, in my pickup in eastern MT summers. Cab, ammo, and rifle can be hot. Had a few loads get squirrely, especially with H335, H414 and W748 many years ago. Mostly use Hogdon H4350 and IMR 8208 now, and load below maximum, and those troubles went away. But often I get better groups near maximum, as Mule Deer has pointed out. I'll give up a little precision for the safety factor.

John55,

Thanks. My next question is: Did you record the temperature when you chronographed the load in early fall?

John55,

Thanks. My next question is: Did you record the temperature when you chronographed the load in early fall?

Low 70s then, mid to upper 20s in January.

Thanks for the info.

Among the things I've learned from various powder manufacturers about tempeatrure-resistant powders is that other factors can affect such powders, including temperatures above about 80. I have yet to find a powder claimed to be temp-resistant that didn't gain consistently measurable velocity above about 80--though all I've tested so far gain far less velocity than what could be called "conventional" powders.

Other factors that can affect temp-sensitivity in colder temps are the specific primer, since they can vary considerably in "hotness," whether so-called standard or magnum primers. More important, apparently, is load density, especially in colder temperatures resistance. Slightly compressed loads are the most consistent.

Another factor I've encountered myself in cold-testing with various chronographs is battery strength. I'm constantly changing and/or heating up primers in cold testing, but I do it at right around zero F.--which chills batteries pretty quickly.

One reason I asked is that I have yet to encounter any load with any Hodgdon Extreme powder that lost more than 25-30 fps between 70 degrees and zero Fahrenheit, and I've tested a bunch of them in a wide variety of cartridges. So something seemed screwy, and seems even screwier after finding your "cold" test took place in the upper 20s. I also have rarely encountered anything like that much difference even in "conventional" powders from the upper 20s to low 70s. Even the most temp-sensitive of older spherical powders (which tend to be the most temp-sensitive) don't normally result in much velocity change in that range. Since your tests were so consistent, I'd be wondering if that particular batch of Retumbo was sub-par.

Could be John, but it’s only batch I’ve used. Primers were 215 Federals, WW cases under 175 partitions. Loads were very mildly compressed.

Have to ask one more question: Was it all from the same manufacturing lot?

Yep, all came out of same 8# jug

Thanks again.

Have been testing powders at different temperatures for close to 30 years now, and Hodgdon Extremes since they appeared a little later, as I recall in the late 1990s. As mentioned earlier, have yet to see even the most temperature-sensitive powders lose 70 fps from the low 70s to high 20s. Generally there's so little difference that it's within the normal range of variation for 5-10 shots taken at the same temperature. Have yet to see any Extreme powder lose even 35 fps between 70 degrees and zero.

Since your instrumentation seems good (plus the double-check of two chronographs) the only conclusion I can come to is that somehow your batch of Retumbo is defective. I am sure Hodgdon would like to hear about it.

Interesting info on R22. Here's my question then, just for clarification: always used H4831 in my .270s with 130 gr. but recently began experimenting with R22: initial loads are much more accurate. Use CCI 200s. I've been waiting for some cooler weather for further experimenting. My hunting with my .270s starts in fall and goes thru the winter for coyotes. As you never know what extremes there will be, now I'm wondering about using it at all, despite the accuracy. But it sounds like you're saying if load development temps are 60-70, and I don't hunt in anything over 80, I won't see big changes in velocity. But what about load development at 60-70, and hunting in say 10-20 degrees in the winter? Also, Is there a better primer for these loads using R22? thank you.

Reloder 22 was one of the two powders I first tested for temp-resistance when I started doing so in the early 1990's, because of erratic results in the field during cold weather. The other was H4831--though not the Extreme version, which appeared several years later, but the original mil-surp powder, because I still had a good supply. Both powder lost considerable velocity from 70 to zero, at least 150 fps.

However, have not temp-tested Reloder 22 since then, and it may be better these days. But don't feel any reason to, since Reloder 23 was specifically introduced as a temp-resistant powder, and doubt Alliant would have introduced it if 22 had changed significantly. (Have tested 23 at various temperatures, among a LOT of other powders, and it's very good. Though as I mentioned above in another post, I have yet to test ANY rifle powder that doesn't gain some velocity (and hence pressure) at temperatures from 80 up. Temp-resistant powders just gain less.

John: Is 23 the same as 22 when it comes to burning properties? On 22, I've used it in temps from the 30s to over 100 in Africa without any observed changes, then again the "30s" isn't really cold to you people from Montana !

I'm using up existing RL-22, replacing it with RL-23.

With '23, no reason to buy '22.

DF

Got it thanks. I need to do the same as I use a LOT of it.

I don’t care what the powder’s reputation or advertisement is.....I assume that heat will increase pressures! Hence the reason, all of my load development on hot days.....preferably the mid- ‘90’s! memtb

Interesting, I built my load up in 50-60deg temps and shot last weekend at over 90deg (.270 145eldx@3000). Using the shooter app I was on the money out to 850 which was as far as I went. Did not Chrono but no sticky bolt or obvious signs of over pressure. It is matters this was all new re22 from this year.

I have never had any issues with RL22. I've used it since 1992 in the 25-06 and later with 185s in the 338WM. Temperature range would be from -40C to +20C. Load testin/development usually done between 0C -10C.

Dozens of deer and antelope have fallen to that load.

If I had not read about it being temperature sensitive, I would never have known.

I have used RL 22 in 7mm Weatherby and later switched to Norma MRP in both 7mm and .300 Weatherby with excellent results. Some sources state the MRP and 22 are the same. I seldom shoot either at temps exceeding 70F so I have not experienced issues. I switched the .300 to RL26 a year or so ago for the copper fouling properties and lost a few FPS but tightened up. What’s a few fps when you are above 3,300 already? For whatever reason, it seems the supply of RL26 has dried up so I’m conserving my last pound of it. Seems to be plenty of 22 in stock locally.

I am not surprised you haven't encountered any problems after developing your loads at 0 C. to -10 C (32 to 14 Fahrenheit), at the temperatures you hunt in.

As I have written about in several places, the big problem with temp-sensitive powders isn't necessarily loss or gain of velocity. After all, most big game is killed at less than 250 yards, even in these days of "long-range hunting," where losing 150 fps in real cold or gaining some in hot weather won't make any difference. And even 150 fps will make less than 2" in point of impact even at 400 yards.

That is, if the change in velocity in cold or heat doesn't substantially change the point of impact at 100 yards. Much of the time it won't. but sometimes it will, and a hunter will never know until shooting the load at different temperatures.

The reason I quit using Reloder 22 for hunting ammo was discovering that in a very accurate .270, a load worked up at "normal" temperatures shifted point of impact three inches sideways at 100 yards at zero Fahrenheit (about -15 C). This was in a very accurate bolt-action rifle.

Most hunters apparently think that a rifle will shoot to exactly the same place at 100 yards in real cold, so only the downrange point of impact is changed. Or if POI does change at 100, it will only be an inch or so up or down. Neither is true--though as already noted, much of the time 100-yard POI is unchanged.

But after a lot of cold-temperature testing I have yet to be able to predict which rifles/loads WILL change 100-yard POI--or in which direction. While sometimes it does shift directly up and down, sometimes it shifts sideways--or both up and down and sideways.Three inches of shift is the most I've seen at 100 yards, and that only occasionally, but two inches is pretty common.

All of which is why I switched to temp-resistant powders for hunting here in Montana as soon as the Hodgdon Extremes appeared in the late 1990s. I have yet to see a temp-resistant powder to measurably change 100-yard POI in real cold--which I define is zero F. or below, because even most "ordinary" powders won't lose velocity or change POI significantly down to around 25 F.

But that switch also reduced the number of "surprises" in hot temperatures as well, say when shooting prairie dogs at 100+ degrees. I have a friend here in Montana who claimed he'd never seen any high pressure from a powder notorious for causing stiff bolt-lift (and even blown primers) in hot prairie dog weather. Of course, PD shooting also normally results in hot barrels as well, especially on hotter days.

Then I started shooting prairie dogs with him, and discovered why he's never had any problems with that powder, while I and a lot of friends have: He HATES hot weather, so only shoots PDs from when they come out of their burrows in early spring to maybe mid-June.

As I have also noted a number of times, even the most temp-sensitive of modern rifle powders are pretty consistent between the 20s and 80s Fahrenheit. Beyond those parameters problems can occur, especially in warm weather when hot barrels can add quite a bit extra to the ambient temperature.

John, I see you mentioned that hot barrels add to the problem. In my first post when I brought this up, I was shooting H1000 at a max load with no issue. As soon as I switched to the R22 load with an already warm barrel, I noticed a sticky bolt. 2nd shot same, 3rd shot was a very hard bolt lift. As you know, it only take 3 consecutive shots in a .257 WM for that barrel to heat up a lot. A 95 degree day and a hot barrel was a combination I will not repeat with R22. I got rid of the rest of it.

I suspect you'll find H1000 a little less "warming" to the barrel!

I have a really good load for 22 with 145 ELD's. Around 3040fps. Book max or slightly above but I worked it up in 50 degree weather. As long as I only use under 60 I figure Ill be ok. Ill check it first cool down we get this fall and make sure. Its too good of a load to just give up on LoL