Temperature sensativity of CFE 223

[Had2muchofForums]

I'm guessing but you also probably drank so much Olympia beer you actually saw Bigfoot.

You do understand I was making light of your argument and chart that you found on the internet. It may be perfectly legit, but it makes me laugh how many people blindly follow something without knowint anything about it. Think about what you said and what I jokingly said. We both drew conclusions without any data, any testing, or any information at all. So why would someone believe your found chart over my statement, they have the exact same evidence!

And, finally, everyone knows Bigfoot lives at the base of Snoqualmie, there's even a sign telling me!! After all, it's in writing and it's telling me so, it must be true, yes?!

 

[Brians356]

It may be perfectly legit, but it makes me laugh how many people blindly follow something without knowint anything about it.

Your comment is generally applicable, but I doubt many on this particular forum would blindly assume that chart represented reality.
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[Had2muchofForums]

Your comment is generally applicable, but I doubt many on this particular forum would blindly assume that chart represented reality.
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That, as well, would be my hope!

 

[Brians356]

That, as well, would be my hope!

At risk of stating the obvious, temperature sensitivity would not be linear across case pressures, so there can be no constant temperature sensitive pressure forcing for a powder, which may be employed in many cartridges, and over a wide range of pressures in a particular cartridge.
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[dmoran]

^^^^ That has been my experience also; sensitivity is not linear.
Some powders are more and/or less sensitive to cool/cold. Others are more and/or less sensitive to warm/hot.
Few that will hold linear trend lines across a whole range of temperature and/or pressure.

 

[Rtheurer]

As I have been told, Load Density in a Particular cartridge plays right into Temperature sensitivity as well.

 

[SG4247]

I have shot many pounds of 8208xbr, and when it got above 90F I started seeing blown primers at published “safe” charge weights! I struggled with my dope because my 200 zero POI was constantly changing .. not good.

Switched to CFE223 and have burned literally a pallet load of it. I shoot monthly matches that go from March thru November - over the last 5 years. No issues with velocity, very little change of my 200 yard zero, or any pressure problems. It could be a little cleaner burning, but it meters superbly, is very forgiving in terms of charge weight and on the shelf at every store in town.

Notice the chart reflects just the opposite for 8208 vs CFE 223.

Test it in your cartridge, may very well be a great powder for your application.

 

[CharlieNC]

So in general when powder suppliers publicize and promote the new reduced temperature sensitive powders, how much data have you seen them present? I recall maybe seeing a few comparisons. With the major interest today, seems a savy supplier would generate and include this for their product line. Minor cost in the overall scheme of things.

 

[SSL]

I seem to remember reading an article years ago that gave the theory that temperature changes affected the same powder differently according to the pressure/volume/configuration of each cartridge. This includes bullet weight. Only a theory and not sure if I buy into it 100%, but is worth considering. Perhaps certain cartridges show little to no variation during temperature extremes while others vary by a larger margin. Perhaps due to varying cartridge efficiency. Only extensive testing can prove or disprove this theory. It will have to be someone else though...it would interfere with my naps!

 

[Bc'z]

And, finally, everyone knows Bigfoot lives at the base of Snoqualmie, there's even a sign telling me!! After all, it's in writing and it's telling me so, it must be true, yes?![/QUOTE]

No....
He lives out here in the Kaliminopsis wilderness in Cave Junction,Selma area.

 

[Milo 2.0]

At risk of stating the obvious, temperature sensitivity would not be linear across case pressures, so there can be no constant temperature sensitive pressure forcing for a powder, which may be employed in many cartridges, and over a wide range of pressures in a particular cartridge.
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So is there a formula as to case fill or pressures needed to aid a person?
If what I have going on does not transition into cooler temps, it'll be 9 mos before I can duplicate the scenario again. Most likely that barrel will be shot out in that time frame if it is a target rifle.
For most of my applications, I do not necessarily need a stable offering, I just deal with it. But in a hunting rifle where 50deg swings during a day can be the norm, I'm probably taking the path of least resistance.

 

[Beau]

There's a whole lot of difference between going from 40,000psi to 50,000 psi and going from 60,000psi to 70,000psi.

And, FYI, AR Comp was tested as only having a 20fps difference from -20F to +160F. That's 0.1111 fps/F.
http://bulletin.accurateshooter.com/tag/ar-comp/

What's real? I don't know, I try to keep things sane and shoot for accuracy & not the fastest velocity possible.

 

[Milo 2.0]

There's a whole lot of difference between going from 40,000psi to 50,000 psi and going from 60,000psi to 70,000psi. That's 0.1111 fps/F.

And, FYI, AR Comp was tested as only having a 20fps difference from -20F to +160F.
http://bulletin.accurateshooter.com/tag/ar-comp/

What's real? I don't know, I try to keep things sane and shoot for accuracy & not the fastest velocity possible.

That's why it's up to each of us to run our own tests. I've watched guys stuff powder into a case way beyond max efficiency of that case to the point velocity was on the decline w/o blowing primers in summer and do an honest test at 0 deg and speeds remained somewhat constant. Then make the claim.
I like to read and garner information like the rest of the crowd, but I'll shoot my own tests.

 

[Rtheurer]

I seem to remember reading an article years ago that gave the theory that temperature changes affected the same powder differently according to the pressure/volume/configuration of each cartridge. This includes bullet weight. Only a theory and not sure if I buy into it 100%, but is worth considering. Perhaps certain cartridges show little to no variation during temperature extremes while others vary by a larger margin. Perhaps due to varying cartridge efficiency. Only extensive testing can prove or disprove this theory. It will have to be someone else though...it would interfere with my naps!

This...

 

[Uncle Ed]

And, finally, everyone knows Bigfoot lives at the base of Snoqualmie, there's even a sign telling me!! After all, it's in writing and it's telling me so, it must be true, yes?!

I have another chart that shows that far more bigfoot sightings are by unemployed loggers who drink Olympia beer.

This chart must be correct because Texicans drinking Lone Star and Pearl beer never see Bigfoot.

WARNING, you know you have had too much Olympia beer to drink when you try to rub something off your back and it turns out to be the floor. This was proven by many times at the McChord AFB, Airman's Club Tacoma, WA.

 

[Brians356]

WARNING, you know you have had too much Olympia beer to drink when you try to rub something off your back and it turns out to be the floor. This was proven by many times at the McChord AFB, Airman's Club Tacoma, WA.

Geez, all you guys had to do was switch from Oly to Rainier Ale, aka "Green Death".
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