Home Forums Reloading Big Game Rifles H4831 vs H4831SC

I was looking on the temperature sensitivity chart and noticed these two versions being different in temp stability value fps/F. The original is 0.36 and the Short cut being 0.08.

Any information about why ? Reading the description says SC is just smaller granules for smoother flow characteristics comes more uniform charge weights, while the individual grains orient more compactly, creating better loading density.

My 300 Weatherby shoots very well with H4831 in the summer months. Never knew how to calculate the FPS/F value. Pressure spikes are minimal in August hot days but come winter different story ? So if it's say 30 degrees F and then come summer it's say 75 you just multiply 45 times the value of 0.36= 16.2 FPS spike. I know it's not exact and some will say there's other ways. I'm not buying a chronograph. I'll just shoot the same load this winter and see.

doing some testing over the years with 4831 and 4831SC, I can tell you, for some reason a lot of the data is on the conservative side, and then some.

Started off in an 06. Saw that its max load was like 58 grains with a 180 gr bullet. However, I noticed the pressure was low for SAAMI specs. Some one asked what was the max load one could get out of an 06. I pondered that and checked out the data., and noticed it was lower pressure than max other powders.

So I just worked up from there, like any other cartridge. Cut to the chase, I found you couldn't get enough 4831 or 4831SC into an 06 case, to exceed SAAMI pressures.. even with a 220 grain.

As far as temp sensitivity, I've hunted with 4831SC in temps running in the 90s, and have hunted with it when I lived in Minnesota down at 30 below zero. Never had an issue with it being able to work and do what it was meant to do.

That's an extremely minimum amount. You probably won't even see a poi shift. I wouldn't waste my money on a chrono for that circumstance either. Yeah, I know: Everyone thinks you need a chronograph to work up a load.

Where did you find this temperature sensitivity chart? I don't recall ever seeing a value below 0.1 fps/F and it has me curious. Regarding the Delta, they may have been tested in different cartridges.

Saw it on long range hunting forum but l think 6.5 Grendel too

They make no such distinction between SC and long cut. Only H and IMR


https://www.longrangehunting.com/attachments/e9c46ecc-d165-450d-a392-9c5238c5fb30-png.160178/

Where did you get your info !😆

Follow the link to longrangehunting.com

Where you said you got it fool.

How’s about the one that’s been posted here quite often

So the chart from longrangehunting is someone's best guess???

"THIS DATA HAS NOT BEEN VERIFIED, YOU SHOULD DO YOUR OWN TESTING"

Yup, grain of salt time. Those charts have been floating around net for about 15 years or so. The only way you are going to know is to chronograph the exact same load at 0 and again at 75. But even then it’s only in your rifle. 10 different people may get 10 different answers.

And these numbers are not results from chronograph testing from 0-75?

No that’s where I stated I did my testing fool. Comprehension isn’t your strong point.
Maybe this will help you.

https://www.handloadermagazine.com/rifle-powder-temperature-sensitivity

Temperature resistance of a specific powder can also vary in different loads and cartridges. In Norma’s first 2004 edition of its hardcover manual, Sven-Eric Johansson of Nexplo/Bofors, the Scandinavian company that manufactures Norma powders, states: “For any caliber, rifle, bullet combination it is possible to engineer a powder that shows little pressure or velocity temperature dependency, but if loaded and shot from any other caliber, rifle, bullet combination, would likely exhibit a totally different temperature-behavior profile.”

There's nowhere in this thread you said it was your testing.

But I'll leave you with this... what a bullet/powder company says is only in thier testing facility, not mine. "would likely exhibit" not WILL exhibit. As like the rest they ARE NOT sure themselves, and either are you

So back to the original post, where is the chart/test showing H4831SC at 0.08 fps/degree?

Thanks, looks like no one in that thread knew the source of that data or test parameters.

I've gathered that the temperature sensitivity of a particular powder may vary depending on the cartridge in which it is being used. A chart with one number assigned to each powder should also set out for which cartridges the number applies.

I have seen charts set up just that way with a few test results. So many variables that I doubt a comprehensive chart will ever be compiled.

I keep things simple and develop maximum loads in our Phoenix summers. Then test velocity drop in the winter if interested in loss. Hard to test below freezing here though and I only have a couple data points.