Temperature Sensitivity of 8 Powders for .223 High Power Service Rifle
- Thread starter BillC79
- Start date
Very good to see some experimentation on this.
The N100 series of powders are very well thought of in Europe as being temperature stable
(The Finns who make Vihtavouri Powder have quite warm summers and winters that even the Russian army thinks is a bit cold so temp stability is a big thing for them).
N140 is usually thought of as being a tad slow for the 55gr bullets in .223 Rem in the UK but it is great with the heavier bullets.
Interestingly, the Canadians seem to like Viht powder and in places like N Alberta it goes from pretty warm to pretty cold as well.
Good post, thanks for sharing!
Scrummy
The N100 series of powders are very well thought of in Europe as being temperature stable
(The Finns who make Vihtavouri Powder have quite warm summers and winters that even the Russian army thinks is a bit cold so temp stability is a big thing for them).
N140 is usually thought of as being a tad slow for the 55gr bullets in .223 Rem in the UK but it is great with the heavier bullets.
Interestingly, the Canadians seem to like Viht powder and in places like N Alberta it goes from pretty warm to pretty cold as well.
Good post, thanks for sharing!
Scrummy
4166 Enduron has become my new best friend. Stable and a
good accuracy level. It reminds me of when Reloder 16 hit the
streets. One powder I would like to see in the mix is Lovex
Precision Rifle powder. It's showing promise on my end, and
working side by side with 4166, It has a much smaller stick
structure then 4166 and just a tad slower.
good accuracy level. It reminds me of when Reloder 16 hit the
streets. One powder I would like to see in the mix is Lovex
Precision Rifle powder. It's showing promise on my end, and
working side by side with 4166, It has a much smaller stick
structure then 4166 and just a tad slower.
BillC79
Gold $$ Contributor
I appreciate your suggestion for improvement. Shooters World Precision Rifle Powder (Lovex S062) should have been in the 77 grain MatchKing test. I have been working on finding a bottle of it with no luck so far. I will update the test results if I can get the powder in a timely manner.
jelenko
Gold $$ Contributor
What would you think of using Gordon's Reloading Tool [GRT] to estimate temperature sensitivity of various powders? The sensitivity to temperature is built into the calculations. I'm assuming - i.e., don't know for sure - that the sensitivity to temperature in GRT is based on the characteristic of the powder.
BillC79
Gold $$ Contributor
It would be interesting for someone with GRT to see how accurate GRT is in predicting the data I obtained. My past experience has been that QuickLOAD is not very accurate in making the predictions, although I have not gone back and checked with the my most recent data.
RegionRat
Gold $$ Contributor
@jelenko @BillC79 think of those math models in the other way, i.e., they rely on experimental data to calibrate the temp sensitivity values, not the other way around.
Don't get me wrong, I am a long time user and fan of Quickload and appreciate its value when it comes to Wildcatting or powder substitutions. However,... it doesn't match results for details like changes in seating depth versus velocity for example, no matter how hard we try, but that is okay. It doesn't mean it doesn't bring value to the table for the efforts. It is good enough.
When we say Quickload is good enough, I am saying I know it doesn't always track things to high resolution such that it would predict Bill's data. Chemistry and thermodynamics in internal ballistics are complex when it comes to modeling things like temperature sensitivity across so many possible cartridge case designs, primers, ingitions, bbls, etc. and a simplified temperature sensitivity coefficient is only going to track reality so well unless it gets a detailed parametric study that would cost a fortune even if it were done for a single caliber, let alone one that would be good across anything we throw at it.
For those models to get better, there has to be multiple tests at multiple labs giving disciplined input to refine those values and that happens over a long time. Parametric models that are subject to so many uncertainties in things like case volume, primers, ignition, chambers, throats, bbls, etc. are always taken with caveats. I would still rather have Quickload when playing way off the map or with different powders than not have it. I just don't expect it to match with high resolution. YMMV
Don't get me wrong, I am a long time user and fan of Quickload and appreciate its value when it comes to Wildcatting or powder substitutions. However,... it doesn't match results for details like changes in seating depth versus velocity for example, no matter how hard we try, but that is okay. It doesn't mean it doesn't bring value to the table for the efforts. It is good enough.
When we say Quickload is good enough, I am saying I know it doesn't always track things to high resolution such that it would predict Bill's data. Chemistry and thermodynamics in internal ballistics are complex when it comes to modeling things like temperature sensitivity across so many possible cartridge case designs, primers, ingitions, bbls, etc. and a simplified temperature sensitivity coefficient is only going to track reality so well unless it gets a detailed parametric study that would cost a fortune even if it were done for a single caliber, let alone one that would be good across anything we throw at it.
For those models to get better, there has to be multiple tests at multiple labs giving disciplined input to refine those values and that happens over a long time. Parametric models that are subject to so many uncertainties in things like case volume, primers, ignition, chambers, throats, bbls, etc. are always taken with caveats. I would still rather have Quickload when playing way off the map or with different powders than not have it. I just don't expect it to match with high resolution. YMMV
urbanrifleman
Site $$ Sponsor
AR Comp still smokes them all in the practical shooting range of say 50 F to 110 F. Lowest spreads too.
urbanrifleman
Site $$ Sponsor
If that is the new N140 and not the old, that performance sucks. It is a straight vertical line.
I am assuming this is the old stuff.
I am assuming this is the old stuff.
RegionRat
Gold $$ Contributor
I would call test like Bill's just as valuable as those values in QL.
The relative ranking in terms of temp sensitivity in QL have been true in terms of helping find the best candidate powders. I am just trying to say that QL shouldn't be expected to predict values that match exact chronograph trends. They come close enough and to do any better will take lots more testing like Bill's.
BillC79
Gold $$ Contributor
QuickLOAD is worthless for predicting temperature sensitivity (or more specifically predicting the slope of the temperature/velocity relationship for the powder.) It appears to assume that all powders are temperature sensitive.
I went back and assessed the function of QuickLOAD in predicting temperature sensitivity with my data. First I adjusted the Ba (burning rate factor) value so that it was calibrated with the data I had for powder, bullet, case volume, temperature and velocity. I then had QuickLOAD calculate velocity predictions for the three temperatures at a given powder charge. The data are below. QuickLOAD assumes that the slope is positive for all four powders I checked regardless of whether the slope is positive, negative or flat.
I went back and assessed the function of QuickLOAD in predicting temperature sensitivity with my data. First I adjusted the Ba (burning rate factor) value so that it was calibrated with the data I had for powder, bullet, case volume, temperature and velocity. I then had QuickLOAD calculate velocity predictions for the three temperatures at a given powder charge. The data are below. QuickLOAD assumes that the slope is positive for all four powders I checked regardless of whether the slope is positive, negative or flat.
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RegionRat
Gold $$ Contributor
And that right there is why Bill is testing. And thanks for sharing your hard work.
It just points to the areas where more work is needed in the models, it doesn't condemn them.
It also points to paying attention to the politician's and environmental trends, just in case...
BillC79
Gold $$ Contributor
My N140 is the "old" formula purchased in 2020 (manufactured in 2017). The new "improved" N140 has a label that states "Decoppering agent and Temperature stable" in the UK according to Laurie Holland in Target Shooter Magazine. Link to article below:
HANDLOADING BENCH BY LAURIE HOLLAND
REACH OUT! – EU COMPLIANT POWDERS Part 1 Thinking of a name for this piece, the 1960s mega-hit for American boy-band The Four Tops popped up in my head. Bad news as Reach Out! [I’ll be there] is one of those tunes you can’t shake off for days. Still, it’s an appropriate bit of plagiarism…
www.targetshooter.co.uk
I found a bottle of the new N140 in stock and will test it against the old.
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urbanrifleman
Site $$ Sponsor
My N140 is the "old" formula purchased in 2020 (manufactured in 2017). The new "improved" N140 has a label that states "Decoppering agent and Temperature stable" in the UK according to Laurie Holland in Target Shooter Magazine. Link to article below:
HANDLOADING BENCH BY LAURIE HOLLAND
REACH OUT! – EU COMPLIANT POWDERS Part 1 Thinking of a name for this piece, the 1960s mega-hit for American boy-band The Four Tops popped up in my head. Bad news as Reach Out! [I’ll be there] is one of those tunes you can’t shake off for days. Still, it’s an appropriate bit of plagiarism…www.targetshooter.co.uk
I found a bottle of the new N140 in stock and will test it against the old.
Yah, I want to see that one.
The old stuff was crazy temp sensitive... pretty much 1 fps/1 F. Or more even.
I shoot the .22 BR with 8 twist bullets. I have shot every powder on the page, including H-4895 which is made in the same factory, with the same equipment as IMR 8208 so I reject the premise that is somehow radically different. I have been lured by the SD that N-140 produces. I have been enjoying wonderful groups (> 2 inch at 540 yards) with N-140 but it seems to be at a different point of impact every trip to the range. Now I know why. I have less experience with AR Comp, accurate enough to suggest further investigation, but I was heartened to see it included. Target dot is 3" distance 550 yards.
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Hengehold
Silver $$ Contributor
Fantastic report, thanks for sharing!
-Trevor
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