CFE 223 is Temp Stable?

[Mrcheesemoose]

So I've heard and read all over the place that CFE 223 is a temp instable powder. So as it gets really hot or really cold, the velocity change is very large. But then I stumbled upon this page: https://www.wlcastleman.com/equip/shoot/t223/index.htm and it seems that CFE 223 is actually temp stable under certain temperatures. So I decided to test it myself. I spent 85 rounds to get a bunch of data shooting at temps between 30 and 80 degrees, then graphed the data, and I'm getting that its as temp stable as Varget. Am I crazy, or my data just really bad? This goes against everything I've read onilne except the page I put earlier. Does anyone have any experience seeing this with CFE 223? Btw I'm testing this for 6 ARC and 223 reminton.

 

[Mrcheesemoose]

I do intend to put more rounds into this at more extreme temps, but this is really surprising to me

 

[flyfisher117]

Was the ammo 100% acclimated to those temps you tested or did you take your ammo from an air conditioned house straight to the range and test it at what ever arbitrary temp it was at?

I worked up a warm load with CFE in the late fall. Early summer the following year it was very spicy and quite a bit faster. Following late fall it settled back in.

 

[Mrcheesemoose]

Was the ammo 100% acclimated to those temps you tested or did you take your ammo from an air conditioned house straight to the range and test it at what ever arbitrary temp it was at?

I worked up a warm load with CFE in the late fall. Early summer the following year it was very spicy and quite a bit faster. Following late fall it settled back in.

Ammo was acclimated, I measured the temps with a laser thermometer to make sure the ammo was up to temp before firing.

 

[slyver11]

I'm not getting huge swings in my 6 arc. I don't shoot in freezing temps though. In 80- 100f it's around 20- 25 fps faster than 40f in fall.

 

[Leaf Litter]

Test it between normal hunting powder temps, let's call it -20°F to 110°F and let us know how it goes.

For what its worth , I work in an industry where temperature control is crucial, and we abandoned laser (IR) thermometers years ago because they just kinda suck. Inconsistent at best and will never yield repeatable results on reflective surfaces. In addition to that, brass temp is not indicative of powder temp. Brass will equilibrate long before powder hits its temperature equilibrium throughout the charge.

I'd love to see CFE 223 be temp stable, just waiting for comprehensive data.

 

[wind gypsy]

Temp stability seems to vary based on cartridge, pressure its loaded to, and how hot or cold the extremes testing are so its easy for statements to be overly simplified and misleading when talking about whether a given powder is/isn't temp sensitive.

 

[Mrcheesemoose]

Yah I'm starting to think the laser thermometers aren't too good, the data I was measuring with them was all over the place and I had to throw a bunch of it out because it made no sense. Instead what I've done with this data is let the ammo sit out for a couple hours at the temp I want it to be at before shooting. Its a little tough because that also means I have to let it sit out on days where the temp is relatively even, so it's been taking me awhile to get data. Starting with the 6 ARC data, this is generally what I'm getting (load is 28.6 CFE 223, 108 eldm):



Nothing in the extreme temps, but its spring here, so we haven't gone above 80 or below 40 for the past couple months. This curve is roughly 1 F / 1 FPS. I'll add to this graph as I get more data. Should have more stuff in the 80s - 90s hopefully soon, and some 223 data too

 

[brazz04]

I'm running CFE in both my 223 and 6 arc rifles, next time I hit the range, I'll throw some in the freezer the night before and keep them cool as well as leave some in the sun while at the range and see what kind of a spread I can get. Seems like a fun little test.

 

[coyotekilla]

My 223 seems to think its kinda sensitive to temp, doesn't like the cold much is what I remember. It does leave a fairly easy to clean bore though.

 

[Bluefish]

The data I found a while back suggests it’s somewhere in the .5 fps/deg at 30-60 and 2 fps/deg above that. You will need more data points to capture that knee.

I found it drops off with lower pressure (40k) loads at cold temps. I now use 2520 instead. Cfe223 can get great speed, but I think it needs higher pressure to work well. I noticed that sd really dropped as I got closer to a max load that is compressed. Back the load off and sd goes up while velocity goes down.

 

[Mrcheesemoose]

The data I found a while back suggests it’s somewhere in the .5 fps/deg at 30-60 and 2 fps/deg above that. You will need more data points to capture that knee.

I found it drops off with lower pressure (40k) loads at cold temps. I now use 2520 instead. Cfe223 can get great speed, but I think it needs higher pressure to work well. I noticed that sd really dropped as I got closer to a max load that is compressed. Back the load off and sd goes up while velocity goes down.

6 ARC is seeming to be landing around 1 fps/deg. I'm gonna get a lot more data at higher temps this summer, then when it gets colder in the fall/winter I'll get some more data there. 1 fps/deg does sound like the right sensitivity though. I think my previous data was way off. But this data looks about right