Home Forums Hunting & Shooting Ask The Gunwriters R22 on a Hot day

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.