Temperature Sensitive Powders ?

[Pineman]

Finally got enough components to start my reloading for 300WSM and 270WSM. I have a couple of questions for people much more knowledgeable than me. In the past I never paid much attention to which powders are more temperature sensitive than others when I reloaded for my 270 win and 30-06. I just found the powder that worked best for my gun and used it. It seems while researching this topic that people are split in their opinions. Some pay allot of attention to temp sensitive powders and others take my approach-find a powder that works good and go with it. I'm looking for opinions from you guys. I should say this will be for hunting and not competition shooting. I would say longest shot maybe 500 yards. Finally, can someone provide a link to a chart where the different powders are listed for sensitivity? I found a couple online but not really what I wanted. TIA

 

[Joec7651]

What powders will you be using?

 

[xphunter]

Finally got enough components to start my reloading for 300WSM and 270WSM. I have a couple of questions for people much more knowledgeable than me. In the past I never paid much attention to which powders are more temperature sensitive than others when I reloaded for my 270 win and 30-06. I just found the powder that worked best for my gun and used it. It seems while researching this topic that people are split in their opinions. Some pay allot of attention to temp sensitive powders and others take my approach-find a powder that works good and go with it. I'm looking for opinions from you guys. I should say this will be for hunting and not competition shooting. I would say longest shot maybe 500 yards. Finally, can someone provide a link to a chart where the different powders are listed for sensitivity? I found a couple online but not really what I wanted. TIA

Sound like you have found a load that shoots good.
On days of very little wind, shoot it at 500 yards on the typical warmest day of your hunting season, and then shoot it at 500 on what would be a colder day.
Put your ammo in the fridge or freezer, then take it in a cooler to keep it cold.
See if it shoots different enough to make a difference on a game animal in terms of accuracy at your max distance.
Then, you will know for yourself if it matters or not.

 

[hunter24605]

I don’t give it a lot of thought because I’m not shooting long distance, and frankly we don’t have much more than 50* difference between average summer and winter temperatures. (30*~80*). I do keep it in mind if it’s winter and I’m running at load that’s close to max, in the summer that same load may be too hot.

 

[Ridge_Runner]

for the most part, double based powders are more temp sensative than single base. look at the ingredients. nitrocellulose is single base, nitrocellulose and nitroglycerine is a double base. However you will get higher MV at the same pressure with double base due to it containing more energy per charge.

 

[JD338]

I've never fully bought into the temp stable powders because all powders are temp sensitive.
I find a load, shoot over the summer out to 800 yards and verify in the fall. I make any necessary adjustments and hunt. I've been doing this for years and it seems to work out for me.

JD338

 

[Pineman]

Joe,
RE 17,19 and 22. H4350, H4831, H4831sc, IMR 4064, IMR 4831, IMR 7828SSC, Magpro, Varget (not much), Superformance

 

[TackDriver284]

I'm starting to stay away from temp sensitive powders when I go to my local store to buy powders or buying them online, sometimes if my rifle shot great with temp sensitive powders , in the node at 70 to 90 degrees but goes out of the node at 50 degrees and shoots poorly instead of that teeny one hole or .25 MOA group I usually make on warm days. It depends on how narrow or wide my node is. I'm starting to like temp stable powders like Varget, H4350, H1000, H4831SC mostly than any other powders, but I still use other temp sensitive powders I have on my shelf. In my local area, its always warm / hot , and when I test those those sensitive temp powders with a certain bullet that shoots great in those warm / hot temperatures, I stick to shooting those temp sensitive powders at those warm / hot temps. Some temp sensitive powders shoots great like RL22 , and I won't shy away from them. My 300 Win Mag loves it. I still have a few pounds of RL26, but have not tried them out yet, until I finish the last pound of that RL22 for my 300.
The powder sensitive chart may be incorrect, but its close. It's what I found on the internet.

 

[Pineman]

TachDriver284
Thanks for the chart. I saw one similar but I like that this one is color coded. I guess as other people have said, I need to find a load that shoots good, try in the summer and then in the fall that closely matches my hunting temps and see if I get any POI shifts.
Thanks for all the replies.

 

[TackDriver284]

TachDriver284
Thanks for the chart. I saw one similar but I like that this one is color coded. I guess as other people have said, I need to find a load that shoots good, try in the summer and then in the fall that closely matches my hunting temps and see if I get any POI shifts.
Thanks for all the replies.

Yes, try and see what your rifle likes and see if you can use a chrono and record your speeds in hot weather and cold weather as well.

 

[wvbuckbuster]

When you find a load that satisfies you and then test it during cooler weather and the velocity drops off or the group size increases more than you can bare just tweak it a little by adding a little more powder to bring back to where it was. Some have been doing this for years. It's a option. Dan.

 

[300WSM]

Finally got enough components to start my reloading for 300WSM and 270WSM. I have a couple of questions for people much more knowledgeable than me. In the past I never paid much attention to which powders are more temperature sensitive than others when I reloaded for my 270 win and 30-06. I just found the powder that worked best for my gun and used it. It seems while researching this topic that people are split in their opinions. Some pay allot of attention to temp sensitive powders and others take my approach-find a powder that works good and go with it. I'm looking for opinions from you guys. I should say this will be for hunting and not competition shooting. I would say longest shot maybe 500 yards. Finally, can someone provide a link to a chart where the different powders are listed for sensitivity? I found a couple online but not really what I wanted. TIA

Aaahhhh...

The decade plus old claim of being impervious to the barometer and powder mfg's are still trying to tout that claim.

#1 I use R17...
Ooohhh it claims to weather the weather...lol...better than most.
OK.
Does it really? Oh yes. Why. The MFG told me so.

How in the hell can we tell that? I mean seriously!!
I can tell you this...I'm a far better barometer from old war wounds than any powder causing an increased group.

Hornady/Hodgdon Superformance told me the same thing.
Were they right? Sure. They said it so it must be so.

My fellow short mag brotha....
Pick one that hits the parameters you seek and roll with it.

Let's just say it really does impact that for a sec....
If you're shooting 1" groups there is no weather, none that you could survive anyways, that would suddenly make your load hit outside the terminal area. If you were achieving a 1" group on pleasant days you're still going to be well within the terminal POI.

I'm in PA and we get some extreme weather here. Ball busting hot in the summer and extremely cold in the winter. Rain to snow and sleet, etc.
The two caliber's used to take more game in this state ( and shot prior to season) are the 30-30 and 30-06 loaded with Winchester power points or Remington Core-lokt.
The powders used of course would be Win760 and whatever IMR worked the cheapest and best for 30-06. Remimgton was Dupont and Dupont was IMR...
Powders certainly made long before the catchy weather impact claim.

If this weather issue was really a concern you'd see all sorts of complaints over the years of accuracy problems weather related from those two calibers being used by the near one million deer hunters in PA.

Nope.
They shoot at target...
Verify "it's still on"
Went hunting

 

[Joec7651]

Mark beat me to the chart. Ya gotta love Excel. Good information.

That being said, I shoot a good bit of IMR 4831, and 7828. My groups don’t change with either from summer to winter, and POI remains consistent. I’m not suggesting you disregard temp stability. It just hasn’t made a difference with my groups. In my rifles if it shoots 1/2-3/4” warm it shoots 1/2-3/4” cold.

I’m sure if I were shooting 1k the difference would cause vertical differences in POI that may affect scores on paper. As it stands, my longest shot anywhere I hunt in the last 7 years has been 356 yards measured by laser. I happened to be carrying a 308 Win loaded with a 150gr Gold Dot bullet, and CFE223 one particular 20 degree morning. My 65ish fps velocity swing and whatever vertical change wasn’t noticed by myself or the doe. Center punched both shoulder blades and it stopped under the hide on her far side. She never took a step. Then I forgot the bullet on the dresser of the Days Inn when I left 3 days later.

I actually hit a little higher than I wanted because I expected more drop. That’s entirely on me, not the temp or powder. I underestimated the “puny“ little 308 because I had been shooting my 7mm Mags most of the summer. Somehow I’d forgotten all the deer it took over previous seasons. Lol

I wanted to drop it in just above the lower leg joint, and below the shoulder blade where there’s only a rib to contend with. If I’d loaded Varget I would have still busted her shoulders and hit a little high of the soft spot. Find a safe, accurate load and hunt with it. If that load is a temp stable powder then great. If not don’t let it eat at you at all.

 

[300WSM]

To add one more thing...

Are you really going to see a barometric difference outside of user error?

So the weather swings...and you shoot a 1.25" group.

Three weeks prior in different weather you shot a .75" group.

Was that .5" increase due to weather or you?

IMO the shooter is much more a variable than the weather.

I can go out on identical weather days and get a .25" difference...possibly more. That's just me.
I can group one ragged hole or a .75" group.
Weather or me?
I'm definitely going with user error more than weather.
Remember you don't always shoot your best group on every outing. We're not robots shooting in controlled environments from a vise.

 

[xphunter]

Finally got enough components to start my reloading for 300WSM and 270WSM. I have a couple of questions for people much more knowledgeable than me. It seems while researching this topic that people are split in their opinions.

I would say longest shot maybe 500 yards.

With a just a maybe for your longest shot being at 500 yards, I would say don't sweat it.
When you shoot your hunting rifle at cold and hot temps at either 400 or 500 yards that you might face in a typical hunting season, you will answer this question for yourself, and the confidence in your load/gun will increase...And that is a good thing!

Lets take a 7mm. 140 grain AB (not a great BC) leaving the muzzle at 2961 fps in 60 degree weather. 100 yard zero.
At 500 yards it drops 46.8 inches and it takes 8.9 MOA (I would dial 9 minutes).
Let's say it is 15 degrees outside and my MV drops 30 fps (2931 fps). 500 yards 9.2 MOA or 48 inches drop
We have 2.2 inches difference in drop at 500 yards. I know very few people who can hold a 1/4 MOA (1.25") on a animal under stress.
2.2" at 500 yards is less than a half MOA (2.5" shooter's MOA).
Depending on the animal you are hunting you will have a 8" kill zone or maybe a 10" kill zone.
If you cut that in half you have 4-5 inches of play on either side of your vertical from center, and the animal to be cleanly killed.
Your ballistic profile for the 270 WSM and the 300 WSM will likely be better than what I listed here.

Wind is where the devil comes in to play
With the load above a 10 mph FV/crosswind at 500 yards is 19.4" of drift
With the load above a 5 mph FV/crosswind at 500 is 9.7" of drift

Depending on the animal you are hunting you will have a 8" kill zone or maybe a 10" kill zone.
If you cut that in half you have 4-5 inches of play on the right or on the left from center, and the animal to be cleanly killed.
Wind will be a bigger variable than your drop will be...

Do you need to know your drops when you stretch things out (25 yard increments for me out to a grand)-Most definitely.
Once your drops are confirmed, practice intentionally in windy conditions(From Field Rests-Get off the Bench)...It will let you know where you are at and what you are capable of.

 

[Pineman]

xphunter:
Thanks for your reply. With the 300 WSM it will mainly be for elk. I have been fortunate over the past few years to take some elk. The distance was 25 yards, 150 yards and 175 yards. With that being said, there are opportunities for much longer shots but probably not over 500 yards. I will practice off my backpack as that is what is the most common shooting position for me.

 

[RL338]

I don’t worry much about powder being temp stable. I mostly shoot between 20*- 80* and our hunting season varies between 20* - 40*. A week before season I check my zeros on rifles I intend to hunt with. With the powders I use , I’ve never seen a load fall apart in 60* swing.

 

[xphunter]

xphunter:
Thanks for your reply. With the 300 WSM it will mainly be for elk. I have been fortunate over the past few years to take some elk. The distance was 25 yards, 150 yards and 175 yards. With that being said, there are opportunities for much longer shots but probably not over 500 yards. I will practice off my backpack as that is what is the most common shooting position for me.

With that kind of a mindset, I expect there to be confidence in your shooting ability, and filled elk tags.
IF, you shoot your hunting rifle in both cold and hot temps at either 400 or 500 yards to see if there is really any vertical change or group size change, shoot off of the bench to remove as much human error as possible

 

[NYDAN]

My view on it is that if I want to start working up a load on a rifle that I haven't loaded for before, there is no downside to start with the less temperature sensitive powders, providing I have them in stock. If not, then I use whatever powder I have in the appropriate burn rate range. If I have to buy a powder, I will buy the more temperature stabile powders if available, if not, then buy whatever is available in the appropriate burn rate range.

 

[DrMike]

I've hunted here in British Columbia in temperatures from plus 27 degrees Celsius to minus 32 degrees Celsius. I've taken game in those temperatures and on numerous occasions between those extremes. I've shot the same cartridge at those extremes. I make my load and I check my load near the temperature I will hunt, adjusting my sights to accommodate the ballistics. Though many of those for whom I worked up loads insisted that I use "temperature sensitive" propellants (though they are actually temperature insensitive), I've never been particularly concerned for my own loads. As has been stated, used a propellant with an appropriate burn rate and test it near the temperatures in which you will hunt, making appropriate adjustments for any velocity variation.