Temp Stability?

[Laelkhunter]

If your target is at 300 yards or less, I don't think you have to worry.

 

[Seabeeken]

How did the shooting world ever get by before the so called temp insensitive powders?

 

[Laelkhunter]

In reply #4 above (thanks fruitnut), he shows at 500' elev, 90* 500 yards shot would be 28.4 inches low with 3213 velocity
move to 6000 feet elevation and lower temp to 50* 500 yard shot would be 29.6 low with 3113 velocity.
raise velocity to 3163 at 50* 500 yard shot would then be 28.2

So, if I was spotting for you and called the range at 500 yards and told you shot will be 28.2 inches low, NOT 29.6 inches. Could you possibly be able to hold a difference of 1.4 inches (in your scope) at 500 yards to make a difference? I don't think I could, so bottom line, I don't think it matters.
It seems we only worry when we handload our own ammo. When we shoot factory ammo, it seems we never worry about temp stability in powder that is loaded in the factory stuff. Not sure why, maybe it's because we have no control over the powder used in factory ammo. We just shoot it and kill stuff.

 

[hemiford]

I thought that the Temp Stability argument was for going overpressure, not POI change, for the most part anyway.

 

[fmuguira]

Hemiford, it's for both but good call out!

Kind of like ES not mattering much at 0-300 yds but start shooting 1000+ on steel and ES does mess with your verticle…..

 

[dogz]

Hi Everyone,
I've read numerous posts indicating that a particular powder is temp sensitive while another isn't. In my case I'm using Reloader-22, a powder that IS temp sensitive, for a 300 Wby hunting load. I'm pushing 180 gr Scirocco 2's at an avg vel of 3213 fps that is dead on at 200 yds. I'm loading them here in Central TX where I'm lucky if its 80-85 degrees in my shop in the AM. When I zeroed it was about 88 deg. I've got a WY elk hunt planned for the 3rd week of Oct near Gillette where average daytime highs are 52 & lows are 30 degrees. I estimate the hunting area is about 6000 ft in elevation vs 545 dt here. Can anyone tell me what sort of impact the temp change will cause or what POI shift I can expect when I get up to WY.
Thanks for your Help!
Happy

How'd the elk hunt go? Hopefully well

 

[MarkInPA]

Can anybody give me a list of temperature insensitive powders? I know about H4350. What resources are available for looking this stuff up? I would be curious to know which powders are insensitive and to what degree?

In the summer, I like to try and shoot at first light in the morning. Temperatures here in PA are usually in the 60's at that time of day. Hunting in December here in PA, our daytime temperatures can vary from 0 to mid 50's. Possibly warmer if we are having above normal temperatures which seems to be more often these days. On average though, I would say that we are hunting in the mid 30's. At our close ranges in the woods, usually under 100 yards, I never worried about it too much. If you have farm land to hunt, you could obviously have much longer ranges.

 

[Turpentine21]

Can anybody give me a list of temperature insensitive powders? I know about H4350. What resources are available for looking this stuff up? I would be curious to know which powders are insensitive and to what degree?

In the summer, I like to try and shoot at first light in the morning. Temperatures here in PA are usually in the 60's at that time of day. Hunting in December here in PA, our daytime temperatures can vary from 0 to mid 50's. Possibly warmer if we are having above normal temperatures which seems to be more often these days. On average though, I would say that we are hunting in the mid 30's. At our close ranges in the woods, usually under 100 yards, I never worried about it too much. If you have farm land to hunt, you could obviously have much longer ranges.

You can go to Hodgdon reloading a see what powders are in their Extreme lineup. These are supposed to be more temp stable. IMRs enduron powders I think are supposed to be as well. Alliant has it written on the individual powders product description. Alliants AR Comp is a powder I have worked with a lot and it is very temp stable. Varget is one of Hodgdons powders that is very temp stable. Although it is an older powder, IMR 4064 has proven that it is relatively insensitive to temp changes as well.

When you get into longer range shooting it helps to have a temp stable powder so you get relatively small vertical poi changes brought on by a substantial change in temperature. Or you get enough of a velocity change to throw you off of your accuracy node.

 

[Darkker]

Can anybody give me a list of temperature insensitive powders? I know about H4350. What resources are available for looking this stuff up? I would be curious to know which powders are insensitive and to what degree?

Anyone who gives you a "list" is simply parroting something they only partially read online.

The fact of the matter is, temperature stability is a designed-for attribute; NOT a universal attribute. The question becomes who built the powder, which isn't any of the names people incorrectly think build powder. And what combination were they designing for.
Private defense contractors, and state-controlled defense conglomerates are the only people actually designing and manufacturing powder.

And yes, the "hype" is very often way, way overblown. Three prime examples:

1) Not many folks actually read very much beyond the length of a TikTok clip. But if you actually read the "data" that was long provided by Hodgdon, a few things should jump out at you. One being that the details of the comparison are non-existent. Another being that they had a comparison to a powder that hasn't existed for almost half a century. And the last that in several cases the "difference" is statisticaly non-existent.

2) Dr. Denton Bramwell did some pressure testing on this subject, in the 223. Going to be hard pressed to find anyone who can't make Varget work very well behind a 55gr bullet. But when you compare it to the 1930's technology of H335(look up the patent date, that's not a joke). Relatively speaking, Varget is a steaming pile in the 223. Clearly it is not, but a lot of folks struggle with elementary level math concepts.

3) The powder ALWAYS gets a bad rep for being the bad guy, but as Denton's work showed; it's actually the powders response to the varied output from the primer. How many ever discuss primer output variability and the actual resultant effects on pressure?
From a bunch of my own pressure testing in the Creedmoor, I can tell you that when you start getting serious with reference ammo calibration. The "insensitive" powders actually speed up and slow down, a rather surprising amount. The difference appears to be the geometry and coatings used for burn rate control, attempting to speed up/slow down based upon the primer impulse.

Was really quite fascinating.

 

[memtb]

My only concern would be uphill/downhill shots being flatter at higher altitude. I ran into this exact problem and shot over the animal twice, the third shot taking him very high in the shoulder disabling him for the finisher. I was aiming at the lower chest, and could not see where the chest stopped due to the Tahr standing in tussock and was partially obscured on the back third.
This event had me re-thinking every uphill/downhill shot ever since, even bamboozled myself on a shot because I didn't use the golden rule "Aim at hair, not air" and the shot went exactly where I was aiming, below the brisket into the ground…
Edit to add: My rangefinder was not adjusted for the elevation, it was still on my home parameters in Australia, not for New Zealand…

Cheers.

After shooting over several animals many years ago, most due to overestimating the distance in late evening……I determined that I will never hold over, unless the distance is measured!

I went to a 300 yard zero, which can easily take me to 400 yards on big game animals …..while "holding on hair"! Generally, animals "way out yonder" offer sufficient time to range them.

Shooting up or down a steep grade certainly "opens a whole different can of worms"! memtb

 

[MagnumManiac]

If I'm not dialing and not ranging, my rifles, stalking rifles only, are set on a MPBR using a 8" maximum, so 4" high, 4" low and works out mostly around a 330yrd zero.
For most deer, this is the perfect size for a kill zone in the vitals hit, has never failed me except for the above scenario when I aimed for air and not hair.

Cheers.

 

[memtb]

I use RL22 often. In my 30-06 there isn't a better powder for 180 class bullets.

When I do summer load development, I'll toss some ammo in the freezer over night then take it straight to the range and shoot it for accuracy.

It's one more check I do only with my hunting ammo. With 30-06 ammo, it's never been enough to worry about the loss in accuracy from other powders.

I do similar….. as I load to maximum or nearly so, all load development done in temperatures at 90+ F. I may shoot at any time of the year…..don't want any unwelcome surprises.

I have an advantage over some…..I just retest in winter, after allowing the rifle and the ammunition to reach ambient. Once the difference in velocities is known and accuracy proven……a simple adjustment fixes the deviation.

No need to carry my ammo around in my pocket! memtb

 

[MagnumManiac]

Can anybody give me a list of temperature insensitive powders? I know about H4350. What resources are available for looking this stuff up? I would be curious to know which powders are insensitive and to what degree?

If you go to the manufacturer of Hodgdon powder, which is Thales/ADI in Australia, where I worked for several years, they have a full statement about their Extreme line, how it came about, why and which powders are included in that make-up.
The Extreme line was initially developed for military purposes of 7.62NATO ammunition made here, it then grew to other powders utilising the same technology. Desert warfare was the catalyst for this development, it changed lots of things.

Cheers.

 

[FEENIX]

Hi Everyone,
I've read numerous posts indicating that a particular powder is temp sensitive while another isn't. In my case I'm using Reloader-22, a powder that IS temp sensitive, for a 300 Wby hunting load. I'm pushing 180 gr Scirocco 2's at an avg vel of 3213 fps that is dead on at 200 yds. I'm loading them here in Central TX where I'm lucky if its 80-85 degrees in my shop in the AM. When I zeroed it was about 88 deg. I've got a WY elk hunt planned for the 3rd week of Oct near Gillette where average daytime highs are 52 & lows are 30 degrees. I estimate the hunting area is about 6000 ft in elevation vs 545 dt here. Can anyone tell me what sort of impact the temp change will cause or what POI shift I can expect when I get up to WY.
Thanks for your Help!
Happy

I hope you had a wonderful and successful hunt. I am late in the game, but here's a quick comparison.