01-23-2022, 05:31 PM (This post was last modified: 01-23-2022, 06:54 PM by Cal.)
Hey Folks,
I've done a lot of reading here and else where (Harpoon1, thanks for the article link)
So I'm finally able/ready to start working up loads for my Gren. What I'm wondering is what kind of difference everyone is seeing with CFE223 vs ambient temperature vs charge weight?
Details:
Rifle type: AR15
Barrel:Heavy Contour 20". Believe it to be a BCA. Marked as 1:8 twist rate (not verified...yet). Have verified COAL to lands = 2.280. Verified with resized dummy round, not able to close bolt by hand with 123 SST loaded to 2.290, can close bolt by hand with 2.280. Required hand pressure same as factory loaded 123 HPBT American Gunner which does function very well. Brass ejects to about the 4:00 o'clock position.
Load Data:
Brass: 1X fired Hornady, 123grn HPBT American Gunner in same rifle. No pressure sings.
Dies : Lee Precision Delux. Brass FL resized per directions in die set. Lite crimp applied with Lee Factory Crimp Die.
Noted observations: The Lee FL sizing/decapping die seems to bring the neck inside diameter to about .260" measured with calipers. When I measure a piece of resized .223 brass, resized with my Lee .223 FL resizing die I get about .220".
Started with CCI #450 primers, 29.0grns CFE223 loaded to 2.260" COAL with Hornady 123SST, increased by 0.3gr increments to 30.8gr. Stopped at 30.8gr due to case fill, I didn't feel any crunching but I don't feel any powder movement when shaking case either. Force needed for bullet seating didn't seem to change. COAL for max load is same as previous loads.
Temperature when loaded, about 40 degrees F.
Loaded 5 rds per charge weight
So what think you my Brothers and Sisters of the Horde?
My 123 Amax load is 31.2grs of CFE at 2.250. As you know, CFE is a bit temperature sensitive. Here are average velocities take on different days out of a 22" barrel at various temps. Measured at the muzzle. As you can see it's all over the map but the trend is upward really spikes over 80 degrees. I'm not confident in those 90 degree numbers. I really need to re-shoot that sometime.
01-23-2022, 06:46 PM (This post was last modified: 01-23-2022, 06:52 PM by VASCAR2.)
My go to load with 123 grain bullets (Nosler CC, SMK) is 31.0 grains CFE223 and CCI 450 in Hornady cases. Ive shot this load at 90 degree temperatures without issue. Here are the velocities I got on a 75 degree day using a Magnettospeed chronograph.
Hand Load 123 Grain Nosler CC, 31.0 grains CFE223, CCI 450
16" 2449
18" 2471
20" 2526
24" 2619
Everything Ive read expect about 1.5 - 1.7 FPS of velocity change per degree of temperature change. In essence 40 degrees compared to 70 degree the CFE223 will produce about 50 FPS less velocity for the 30 degree cooler temperature.
Maybe I should load up 1 more charge @ 31.1grs. I guess a big part of my question hinges on avg ambient temp at loading vs avg ambient temp at use and what may change.
Or am I headed down a deep dark rabbit hole that just eats up lots of resources for little to no gain?
01-23-2022, 10:54 PM (This post was last modified: 01-23-2022, 11:00 PM by Happy2Shoot.)
biodsl Wrote:My 123 Amax load is 31.2grs of CFE at 2.250. As you know, CFE is a bit temperature sensitive. Here are average velocities take on different days out of a 22" barrel at various temps. Measured at the muzzle. As you can see it's all over the map but the trend is upward really spikes over 80 degrees. I'm not confident in those 90 degree numbers. I really need to re-shoot that sometime.
Good job H2S.
Not surprising that CFE223 has a 3.2 fps/F. Most ball powders are more temperature sensitive than extruded powders. possibly Winchester Staball 6.5 to be the exception, but it's burn rate is too slow for the 6.5 Grendel for optimum usage.
another powder that works well with 120 to 130gr. bullet in the 6.5 Grendel is Hodgdon H4895. Made by Australian Defense Industries (ADI). It is one of Hodgdon's "extreme" powders. No de-copper agent but the tempco is 0.2 fps/F. so over 10x better on the temp coefficient issue. It also burn quite uniformly and when the right load is reached SDs can also be low with it. And it ignites much easier than ball powders do, similar to most stick powders. It's pretty fine grained as stick powders go so thrown charges don't vary too much. of course if your going for max precision one tends to weigh each charge anyway, regardless of powder type.
you might give H4895 a consideration if low temp co's are important to you. Otherwise CFE223 has that de-coppering agent in it, which is nice, and one gets good velocity and loading density in the 6.5 Grendel with it as well. So other than temp coefficient CFE223 has a lot to offer with the heavier bullets in the 6.5 Grendel in my opinion.
regards,
-tdbru
01-24-2022, 02:49 AM (This post was last modified: 01-24-2022, 02:51 AM by Cal.)
Thank you folks for the info. I'll be back here when I get these launched to add my results to the data.
Guess I'll need to look at getting some H4895.
Long story short, I do have some Accurate LT-32 coming also.
I gave up on cfe223 some time in 2021 maybe even closer too 2020 time frame.
Good powder never acted spikey but the huge velocity loss from normal temps too coldfront temps while hunting was just to much for my taste. Plus every load I worked up for it went to crap when the temps dropped.
Most loads I used it in I moved over too arcomp. The bolt grendel loads I used cfe223 in got h4895 or varget but my bolt loads are way longer then will ever fit in a ar15 grendel mag and dont fit in stock cz grendel mags. My mags have been modified to fit a longer coal length.
I used to use CFE223 all the time. I noticed in my gun that the loads I would develop at a temp would lose accuracy and have POI shifts with temp changes. I used CFE223 before Hodgdon had it listed on their website data for the Grendel. I looked a few weeks ago and they have pulled it again.
I have moved on to TAC and have found a much larger accuracy node and am hoping for enough temp stability to make it useful for hunting.
myrifle Wrote:I gave up on cfe223 some time in 2021 maybe even closer too 2020 time frame.
Good powder never acted spikey but the huge velocity loss from normal temps too coldfront temps while hunting was just to much for my taste. Plus every load I worked up for it went to crap when the temps dropped.
Most loads I used it in I moved over too arcomp. The bolt grendel loads I used cfe223 in got h4895 or varget but my bolt loads are way longer then will ever fit in a ar15 grendel mag and dont fit in stock cz grendel mags. My mags have been modified to fit a longer coal length.
Thanks everybody, I've started out with CFE223 cause that's what I have. With all the problems though, maybe I'll keep it for my .223 and 300yrds and under.
Does anyone have experience with Accurate LT-32? Midsouth had it in and my Lee loading manual shows data for it.
Cal... LT-32 might be a little too fast for 120/123gn bullets. It might be OK for bullets at or under 100gns. If you can roundup some ARComp it looks like the best bet. Power Pro Varmint, TAC or W748 are other options.
I refuse to be victimized by notions of virtuous behavior.
Hodgdon has load data for LT-32 with the 123gr Lapua Scenar. Their max load is 23.5gr loaded to a 2.260 COAL, their showing a velocity of 2204fps with pressure of 51600psi.
Interestingly Hodgdon doesn't even show H4895 as a powder for Grendel. They don't show CFE223 as a powder for Grendel either.
On this info, I did stipulate 123gr bullet weight.
Update, interesting to me anyway.
I had ordered the Hornady Bullet comparator kit, it arrived earlier this afternoon. I figured what the heck, measure my reloads against the factory ammo I have.
What I do know about this rifle is that it shoots about a 3" group @ 100yds with the Gunner ammo. That's the only ammo I've run through it due to lack of reloading dies and supplies.
The other piece of kit that I've finally been able to get is a Magneeto Speed chrono.
Yeppers, gotta play with it. Gonna chrono the Gunner, ELD-M's and my reloads. I was just thinking that maybe I should seat my reloads about .01 deeper.
Cal Wrote:Update, interesting to me anyway.
I had ordered the Hornady Bullet comparator kit, it arrived earlier this afternoon. I figured what the heck, measure my reloads against the factory ammo I have.
What I do know about this rifle is that it shoots about a 3" group @ 100yds with the Gunner ammo. That's the only ammo I've run through it due to lack of reloading dies and supplies.
The other piece of kit that I've finally been able to get is a Magneeto Speed chrono.
Yeppers, gotta play with it. Gonna chrono the Gunner, ELD-M's and my reloads. I was just thinking that maybe I should seat my reloads about .01 deeper.
Any thoughts on that?
Powder charge first, seating depth second.
Find the charge that's safe and gives the sd/es numbers and average velocity your looking for and then try diffrent seating depths to time the bullets travel and exit so it's not traveling or exiting with the harmonics (wave) down the barrel.
Do you have the modified case kit? that way you can measure each bullet to the lands.
The Hornady word on sst's is they do well at about 2.245-2.250, they don't seem to mind the jump which can be up to 100 thou.
Fo an AR style rifle the mag length usually is the limiting factor as to how far out you can go. With some mags you can get out to 2.290 give or take, but knowing that measure where it hits the lands is crucial.
Accurate shooter has some interesting articles on bullet jump, and for most bullets they suggest that somewhere 60-90 or so jump is maybe not the "sweetest" spot but it is the one where you don't have to continually adjust COAL to follow your lands over time.
But the only way you find out what your tube will like is to shoot and experiment with it.
ps, for BCA and typical rack grade barrels, it may take ~100 rounds before the barrel starts to settle in... plus you might get ~50 extra fps at that point (meaning for a given MV you might also need to re-adjust your powder charge up or down a tad).
It's all good and part of the journey.
"Down the floor, out the door, Go Brandon Go!!!!!"
