Here's question for Mule Deer or others that reload for the 7mm Remington Magnum.

I know that lots of folks like RL 22 for the 7mm RM. I understand it is fairly temperature sensitive. What would be a good choice for a less temperature sensitive powder using 150-160 grain bullets?

I rarely hunt in temperatures below 20F and more often in temperatures in the 30's and 40's so perhaps this isn't that big an issue. How much velocity would I lose at these temperatures with RL 22?

Thanks for your help!

Reloder 22 is a great powder in the 7mm RM for the temperatures you hunt in. If it's working for your rifle, I wouldn't change it.

Temp-resistant powders are really only useful when temperatures range 100 degrees or more, and even then may only make a difference at ranges beyond 300 yards, which is as far as most hunters tend to shoot.

If you want some recommendations for other powders I can provide 'em, but it's hard to beat RL-22 for your purposes.

Thanks John! I'm just starting to load for this cartridge so it sounds like RL 22 is a great place to start.

I took MD's rec on this same subject a while back. So far it's the most versatile powder I've tried. I've found consistently accurate loads for 140-160gr bullets.

I'm not sure if I'm understanding you right. If you worked up a load with RL-22 on a 60* day, are you saying that it wouldn't be an issue down to -10* or up to 110*? (so it would be + or - 50* for a total of 100 temp range)

Or are you saying that it would only be an issue if temps were above 100*?

I like h1000 with 150s

Evidently I failed to communicate.

What I meant was that in temperatures ranging 100 degrees F. from minimum to maximum there usually will be a significant change in velocity or poiny of impact, especially at longer ranges.

bowman-if you're up for trying others 7828 is another good place to be.

Dober

Yep, along with H4831, H1000, MagPro, Magnum, Retumbo, RL-25, etc. I've gotten great results from all in the 7mm RM. No need to limit yourself to one powder!

FWIW, my rifle really likes H4831 and 160 grain bullets (haven't tried one it didn't like, including Partitions). I could probably squeeze more velocity out of it, but I get right at 3000 fps and am happy with it.

There ain't much on earth short of elephants you can't kill with a 160 Partition at 3000.

rl22 and rl19 are 2 powders that i have stay away from here where i live . it sucks too because i had a load that was rocking in my 7mags with rl22 . always shot great on 40 to 50 degree days and then one day at the range it was 88 degrees . it was blowing primers out of the case . is reloader series powders made more to shoot out west ?

7mmshawn-was that about the summer of 01?

Dober

I have been shooting RE22 for as long as I can remember. I've hunted and shot with it all over the western US, in multiple calibers. I have asked RE22 to drive light bullets fast, and heavy bullets slow. I've stuck it in .223 cases, RUM cases, and everything betwixt. From about 10 below to Hades... I've not seen it do anything funky.... at least not because of temp.... lot to lot, ehhhhh.

Is it temp. sensitive? yeah, a little... but I've not found a powder that truly is.... no matter the label and marketing hype. If it's freezin azz.... you should add a click or two out past sane ranges.... converse if you're rockchuckin' in June.

Far as the 7RM + RE22.... match made in heaven.... as long as you only want to shoot 110-180 grain bullets. I just loaded up 250 rounds of 7RM using 63gr RE22 pushing the 162 Amax at 3k... this load shoots about MOA to a K pretty easily in a factory 24" sporter.

Dober's 7828 is RE22's kissin' cousin.... I've found it runs well in all conditions/bullet weights too.

im guessing it was about 04 , but the powder could have been about 3 or 4 years old when i shot it . a buddy give it to me to try . im not sure if its the heat spikes or the humidity differences here in the south but hercules powders just dont mix good here . ive seen it several times , even a 7-30 waters contender back when they made rl12 . it sucks too because it seems to shoot really well . a local gun shop here in asheville wont even sell alliant , hercules powders here for those reasons .

Retumbo...

There was a very hot lot of R22 going around the summer of 01. I might be able to recall the lot number if I think about it. I loaded 50 rounds for my .270 right b4 I was taking off for my guiding season and shot a couple b4 I left and oucha they were hot.

I ended up pulling them all when I had time and ended up
taking my 6/06 for my guiding.

Long and the short I've burned a lot of R22 over the years and have never seen anything like that b4 then and in the 11 years since.

Just a thought.

Dober

Dober

i know guys who have shot retumbo and it shoots decent , but it didnt seem very consistent in my gun and felt recoil was alot more with retumbo for some reason . i dont think i ever found a primer it liked with retumbo in my gun but it did shoot better with a winchester standard rather than a magnum which is weird because it fills the case pretty good .

thanks for letting me know , i would like to try it again , ive just been hesitant to do so . guys tell me its the elevation difference , humidity difference or heat here in nc that caused it but i dont really know . i just know ive seen it do some crazy stuff that i couldnt explain .

Thanks for all the suggestions! I'll start with RL 22 and see how things go. Most likely I'll be developing loads at 60-70F and hunting with them between 80F max (early deer/antelope)and 20F min (late elk/deer) and it sounds like that should work OK.

7828 is all i shoot

I like RL22 and most recently have been having exceptional accuracy with H1000. Burns very clean too. I also have had good luck with RL19 and 140 NBT's. I've not noticed any temp. problems with RL powders but don't shoot/hunt much when it's hot either.

It's my thought that IMR 7828 was developed especially for the 7RM. Anyone out there no for sure?

JB can tell us for sure I'd bet but that's the rumor I'd always heard as well.

Dober

My experience with 7828...

I had to back off a load that was developed in sud 60 degree temps by a full grain when temps reached over 80 degrees. Loads were for a .300 Weatherby using 180gr Partitions.

My accuracy loads for a couple of 7RMs have been with 7828.

I had always heard that IMR7828 was Winchester's choice for the .264 Mangleum. It's one of the VERY few times a canister powder was used for a factory load.

On so-called temperature insensitive powders, there are so many "yes but" and "only if" and "except when" disclaimers attached to them that I treat such advertising claims as essentially meaningless.

aj300mag-do you recall what the speed was of the load and how many grains of 7828 you were running? Also, was it from the same lot?

I'd bet that the 60 degree load was running on the edge and the xtra 20 put it over. Maybe...?

Thx
Dober

I pulled a factory 140 power point a few years ago, it looks like they switched to some sort of ball powder that looked a lot like 780

I'd heard that, but have never dissected a factory round of .264. That's why I used the past tense.

Sorry for the temporary thread derail.

Not a 7mm. but have loaded RL-22 in the .300 Win. A perfect match with 180's most of the time. I have chronographed RL-22 from the mid ninety degress to 23 degrees and it lost right at 2 feet per second per degree of temperature reduction. I have found that different lots can vary, sometimes quite a bit. Though I don't get the high velocities that can be attained with RL-22, I have found that the Hodgdon Extremes seem to be much more consistant. Maybe, if using RL-22, buy a 5 pound jug and develope a summer and winter load ?
FWIW,
Jim

Mark IIRC when I originally worked up the load in cool weather I had backed off a load that had a stiff bolt by 1/2 grain. That load (I settled on) was one grain below the max load listed in the Nosler manual. Once the temps here reached 80 degrees that load brought back the stiff bolt on opening and the primer pockets were taking a pounding. Velocity was in the 3150fps range.

All loads were with the same lot number.

I've also had excellent results using IMR4831 in the 7mmRM.

Thx AJ-this is just me and not trying to rebuke or anything but if the bolts a bit stiff in cold weather then it's a safe bet that as it warms up it's definately gonna be hot.

Reducing it by 1/2 grain to me would mean something in a small case like a 223 or 17 Rem but in a big jug like the 300 Wby it's not gonna be enough. I'd say something along the lines of 1-2 grains was more along the lines of what was needed but that's just a swag.

Thx for the nice discussion.

Dober

I've done lots of handloading for 7mm's - mostly 7RM and 7WSM's. Were it me, I'd concentrate on H4831 with 140/150 gr pills and Magnum for 160's. H 4831 will work with the 160's, in fact has shot some of the smallest groups, but Magnum will get almost as small of groups but give 75-100 ft/sec more velocity. 72.0 gr Magnum in my current 24" 7WSM under a 160 Partition gets 3050 with sub MOA groups. 63.5 of H4831 under the same bullet nets 2950 and sub MOA.

I've had really good luck with IMR 7828 and Re 22 as well - but acheive the same thing with H4831 and Magnum so have switched to them and don't worry about temps.

Jack O'Connor wrote that in one of his books.

I know they're using canister 780 in at least one factory load these days.

I pulled a Winchester Supreme .270 Win 140gr Accubond (because they shot so dang good in my rifle). There was a ball powder in it that weighed 57.5gr. Hodgdon data listed 58gr as max with a 140gr Swift, so I bought a pound of 780 and worked up a load with Accubonds. Sure enough, when I got to 57.5gr, it clocked the exact same speed as the Winchester Supreme factory loads, so it appears to be canister powder in that load at least.

Thanks Mark. Your feedback is always greatly appreciated! I know you fall into the BTDT category...

Once again, the reason I prefer the term temperature resistant because there is no truly temperature-proof powder--yet.

The powders that have done best in my own tests have all essentially chronographed the same at zero and 70 Fahrenheit. Not many powders do that, but some do, notably all the Hodgdon Extremes I've tested, plus Ramshot TAC and Big Game.

But even all those powders tend to increase in velocity at temperatures over 70. The increase isn't as much as with standard powders, often only half as much. But apparently no powder company so far has figured out how to produce powders that are velocity (and hence pressure) stable in temmperatures over 70.

Some powders aren't quite as temp-stable as those I just listed bit better than average. In that class I'd put Reloder 15, plus Ramshot Hunter and Magnum.

The claims for temp-resistance aren't BS, as some have suggested, but there are limitations to the technology powder manufacturers now have. Plus, sometimes other variables will affect even the most temp-resistant powders. A ballistic lab tech (who has done a lot more temp-testing than I have) once explained that stressing a powder doesn't help its temp-resistance.

By this he meant using it for less than ideal purposes What he calls ideal is a load that fills the case and produces about all the velocity a certain case and bullet weight are capable of, at safe pressures. The example he gave of a stressed powder is Varget and a 140-grain bullet in the .260 Remington. While accuracy might be good, the powder charge won't fill the case or produce top velocities--and Varget won't be nearly as temp-resistant as it would be with a lighter bullet, or H4350 would be with a 140.

Well, time for some input here that contradicts what has been posted.

I shoot both rifles and shotguns competitively. From very recent experience (Sunday), I can say for certainty that H-4350 is not temperature insensitive as is claimed.

I shoot a 6.5 Creedmoor with 41.3 grains of H-4350. I've been using the same lot of powder since the warmer Summer months. Just last week I checked long range data by shooting. The data had not changed. Temperature was 57 degrees and was entered into Ballistic AE along with the other atmospheric data.

On Sunday we had our little local Precision Match. It was very cold all day with the temperature from 36 degrees to 41 degrees at the end of the match. When targets were engaged at 760 yards, impacts were .2 Mils low. I thought my zero was off, not the drop data, so I added .2 mils to my zero.

Had many chances to check the 100 yard zero as we shoot paper during the match. Well, it was now .2 mils too high. I moved it back to the original zero. As long range targets were engaged, everything was low. I can only attribute the change in drop data to the cold temperatures decreasing velocity.

Ballistic AE has a "temperature sensitivity" parameter in the rifle profile reloading set up page where a number can be input as a decrease/increase in velocity per degree of temperature change. I had never used this part of the program. I entered "3" as in 3 fps change per degree of temperature and the output matched my actual for Sunday's shoot at the colder temperature. The temperature at the time of load development was 55 degrees giving a velocity of 2785 fps. After the conditions on Sunday were input with the Sensitivity feature enabled, the program output that the velocity was now 2743 fps and gave proper data for drop.

With H-4350's reputation as very insensitive to temperature, I was very surprised to see this. I also now believe that ALL powders have to be sensitive to temperature changes.

I've had that same experience with RL 22 in a .30-06 Imp. Scared the Schitt outta me. Haven't used '22 since.

IIRC, the Sierra Manual ran some tests on temp sensitivity. They ran a couple of different IMR powders.

It ran 2 fps/deg F. So, a 100 deg diff is 200 fps and a 50 deg diff is 100 fps. I can see 200 fps throwing things off a bit at a fair distance.

Temperture sensitivity, as explained to me by a tech at Western Powders, can vary. The variations are dependent on the load, cartrage,lot, etc. What might be very tempt stable in one cartrige ( load ) might not be the same as in another.
Just my understanding.
FWIW,
Jim

40 fps throws things off at distance....if you care to hit what you are shooting at.

Good thoughts here guys, nice to see the positive back and forths. A couple other thoughts, I used to run my loads at max with about every trick imaginable. For the most part now I run up to what appears to max and then back off 50-100 fps.

2ndly, all the powders I've worked with over the years can and do vary lot to lot as much as 100 fps. Another reason I'm not a fan of running a round to the nuts anymore. And trust me as I've said b4 I'm a past president of the red-liners club.

3rdly, how often do you guys or how many times (different trips and conditions) do you guys clock a load b4 you feel comfy that the speed you feel it's going that it's actually going? Point being, lots of times I've seen different readings from trip to trip to the range. My guess is it has something to do with lighting?

As to H4350, I've run it a ton since it came out in 1984 or 85 or whatever it is. No doubt it's one of my favs but it does move around a bit as temps change. Or at least that's what I've seen thru my tests. To date I've not found a powder that wouldn't. Some of them more and some less but to date all have. The one brand I've done hardly any work with and no personal work in terms of temp changes is the Ramshot Brand so I can't comment on that one.

It's all good and fun I guess.

Lifes short, hunt hard!

Dober

Only in the past year around the 'Fire did I learn that temp sensitivity is really something to worry about. I've also learned that chronographs can really screw up good loads. I stumbled through the past 41 years of hunting being naive, and it's kind of nice.

rcamuglia,

I would contact Hodgdon and tell them your H4350 experience. Your lot of powder might be defective.

I've talked to a few powder manufacturers, and while they won't tell any journalist everything (for obvious reasons in a very competitive business), but they have admitted that lot-to-lot uniformity of any powder is difficult, mostly due to differences in atmospheric moisture.

My last test with H4350 was with a 7x57 and 140-grain bullets. I run my cold-change tests by chronographing on different days, one as close to 70 as possible and the other as close to zero as possible. The rifle and ammo are at the same temperature as the air (for the cold tests I leave them in an unheated garage overnight), and the same chronograph is used. I also run point-of-impact tests at the same time. At 70 degrees the load chronographed 2842 fps, at zero 2834, which is as little (or even less) variation than usually occurs between shot strings on the same day.

That test just confirmed a LOT of chronographing of H4350 loads I've done in varying conditions over the years. I certainly wouldn't expect the difference you encountered, which is why I suggest contacting Hodgdon.

At 760 yards I'd bet the difference in air density has more effect on POI than temp sensitivity of H4350.

His ballistics program compensates for air density.

Another great reason to buy powder by the 8# keg...

...and it did.

It showed a small increase in drop at 760 yards. 5.1 mils to 5.2 mils with the change in atmosphere.

When I saw impacts at 760 still low I added .2 mils to my zero and I was then high by .2 mils at 100. .2 mils is a lot! Nothing has changed with my load. I shot a group after the match that was 5 shots in 3/8"

The only thing possible to affect drop like it did was temperature which is a big factor in all chemical reactions including combustion

I'll do some actual chrono work to try to find out what's going on.

What if the 8# keg is defective? Then you're stuck with 7.9# of defective powder...

I'll be real interested to hear your results.

If they're consistent with the drop, I'd definitely contact Hodgdon. In my experience they're great people who are concerned about their products.

The chemical and physical compensation in powders for colder temperatures has been explored on the Campfire in the past couple of years. Let's just say that it DOES work, but as I noted in my earlier post, powders do vary from lot to lot. Dober mentioned the bad batch of RL-22 that got out about a decade ago. It was actually closer to Rl-19 in burning rate--and it was recalled. I've also seen considerable variations when a commercial powder was formulated to replace a mil-surp powder--and not just with the old H4831.

10-4

I'll keep everyone posted, but not till this weekend.

How could the lot to lot variation - moisture related - be eliminated?

Could they dry each lot in a big, mild, oven, removing all the moisture?

If that is too big an exercise, could we reloaders dry our powder somehow to ensure lot consistency?

Don't get me wrong. I am not close enough to the margin to need to do this, just wondering if it could be an answer. Always thinking of dumb ideas...

I'd sure take that chance for the known value of a big consistent lot.

The lot I have started with me as two 8#'ers. All that is left is about 2 pounds of the 16#.

Just bought another 16#s

I didn't notice any temperature sensitivity till now, but most of the powder was burned in temperatures much warmer than what we are having now.

I was checking the weather report for this week.

It looks like I'll be able to really get some good data about the temperature sensitivity of H-4350 if I chrono today and tomorrow....







LOL!





******************************************

....I'd back off a grain on Friday....

Should be a good day for getting good speeds...

Dober

dober I wouldn't post results....some one will squawk the loads were over SAAMI spec...

I'm for betting that the 280 AI guys are all lined up to clock tomorrow...<g>

Dober

LOL....