Max loads

[cory]

I was trying to figure out the best way to put out this information and realized it'd be nice to have a thread that contained all LOADS that have shown an initial pressure spike, found through real world data, indicating that we had gone beyond safe pressures. Especially for the less common loads.

These loads are meant as MAX Loads that the reloader should remain below to maintain safe pressures.

Powder - Charge - Bullet Weight/Manufacturer/Type - Velocity/Barrel Length
CFE 223 - 31.4gr - Hornady/140gr/SST & HPBT - 2455fps/ 16"

[cory]

Over the last several months I've sporadically been working on loads for Hornady 140gr Pills. I've been working on the SST and HPBT independent from one another in the same rifle. With both I came to the conclusion the 31.4gr of CFE 223 was where I saw the initial pressure spike indicating I had gone beyond max safe loads.

I'll be posting a full report of my findings with these pills soon.

If anybody has similar loads to share, please do. I'll add them to the initial thread if you can provide them in the format in the original thread. Moderator feel free to edit my original post if someone adds a load and I don't get to it.

[pds]

Cory,
Since LRRPF52 per his post of 2/18/2015 (http://www.65grendel.com/forum/showt...r.-SST-s/page2) considers 31.5 gr. of CFE a safe max load for 123 gr bullets. Your load of 31.5 gr of CFE and a 140 gr. bullet is likely well above SAAMI maximum chamber pressures for the Grendel.

pds

[cory]

I get that man. Here's my data points thus far. Let me know what y'all think.





My node seems that it is going to be at 30.3gr.

[JASmith]

CFE 223 seems to be a very interesting powder and seems to work well in the compressed mode. Nonetheless, I would feel most comfortable if one of us could run tests at 10 - 15 F and at 115 - 120 F to see whether any issues pop up.

I just looked at the QuickLoad calculation of case fill. The 140gr MatchKing at a COL of 2.260" fills the case to almost 109% of case volume.

I already know there is something way off kilter in the burn rate coefficients so the pressure and velocity results are next to useless.

The volumes for this powder, at least, seem about right.

Some have raised concerns about the significant compression results in some bullets creeping out a bit after seating. So far, I haven't detected creep at fills of 108% (8% compression) and would like to hear more.

[pds]

CFE 223 seems to be a very interesting powder and seems to work well in the compressed mode. Nonetheless, I would feel most comfortable if one of us could run tests at 10 - 15 F and at 115 - 120 F to see whether any issues pop up.

I just looked at the QuickLoad calculation of case fill. The 140gr MatchKing at a COL of 2.260" fills the case to almost 109% of case volume.

I already know there is something way off kilter in the burn rate coefficients so the pressure and velocity results are next to useless.

The volumes for this powder, at least, seem about right.

Some have raised concerns about the significant compression results in some bullets creeping out a bit after seating. So far, I haven't detected creep at fills of 108% (8% compression) and would like to hear more.

JA
While not the temperature extreme your looking for I ran this temp test last summer using CFE.


CFE Temperature Test (5/31/2014)

The issue of the temperature sensitivity of CFE powder has been brought up several
times on this forum. I decided to run the following test. I loaded 10 rounds of AA
cases with 31.0gr. of CFE powder, Rem 7 1/2 primers, and 123gr. Nosler CCBT bullets.
I loaded 5 of these in a magazine and put them in my freezer for about 8 hours. I
then packed the magazine between two packs of frozen blue ice then wrapped them in
two towels before heading to the range. Once at the range I placed the other 5 rounds in the front seat of my car for about an hour with windows rolled up in the sun. Outside temp was upper 70's. The gun used is a PF Grendel upper with a 22" Bartlein barrel.
When everything was set up I shot the 'cold' rounds first. I would guess that they were well below 32 degrees as I noticed that there was frost forming on the bullets as I loaded the magazine in the rifle. All 5 rounds were fired within less than one minute. I then shot the 'hot' rounds which I estimate to be at a temp of 85-90 degrees.
The velocity results using a Magnetospeed:

Cold Rounds
1-2442 fps
2-2510 fps
3-2490 fps
4-2480 fps
5-2485 fps
Min=2442 fps, Max=2510 fps
Avg=2481 fps
ES=68 fps
SD=24.7

Hot Rounds
1-2553 fps
2-2565 fps
3-2565 fps
4-2553 fps
5-2552 fps
Min=2552 fps, Max=2565 fps
Avg=2557 fps
ES=13 fps
SD=6.7

While the sample size is small, but with a difference of 76 fps average velocity between cold and hot rounds it appears that CFE is a temperature sensitive powder.
I hope this is useful info for everyone.

pds

[JASmith]

Thanks!

I ran a 9-shot string last week with 31.9 gr CFE behind the 123 gr A-Max at a length of 2.245" when the temperature was 86 F. The load was compressed by 8% per QuickLoad.

Results:

• Magnetospeed Velocity: 2527 fps
• SD = 12 fps
• ES = 36 fps

I had done a couple of ladder tests at 61 F and 66 F with only the vaguest of indications that the velocity trend was higher. Indeed the small scatter was about the same as the differences, so I can't yet draw a conclusion.