Question about temp sensitive powders -- CFE 223 & Leverevolution

[BiggBeans]

Just built a new custom bolt gun in 6mm arc. Will be using it for long range varmint hunting. I have about 5 pounds of cfe and 8 pounds of lever on the shelf. everything ive ever loaded for ive always used hornady extreme powders, which are relatively temp stable. do you guys do anything different when loading with temp sensitive powders? how do you make up for the instability when using your kestrels or ballistics apps? first time running into this issue and it has me wondering alot of things. is it a waste of time building a custom bolt gun and then running powders like these? have you guys had good luck running these type of powders in your long range rigs even with the temp issue? just have alot of questions

 

[redbullitt]

I simply avoid hot loadings with powders known to be temp sensitive... and I generally try for a powder with good stability for my precision work.

Just depends on your goals and what your target is! Cfe 223 shoots very well in carbine applications and practical stuff for me in 5.56. I have not used it much for high precision stuff. It meters well for sure .

 

[Ndbowhunter]

waste of time?

maybe?

probably depends on what ur after. i use lever when the extra velocity actually helps.. aka hunting in the fall. the slight increase or decrease in velocity during hunting season at the distances that are plus side of 1800fps is negligible.

testing ur shit doesn't hurt tho either. the you know, and not guessing off what some retard posted on the internet.

 

[BiggBeans]

waste of time?

maybe?

probably depends on what ur after. i use lever when the extra velocity actually helps.. aka hunting in the fall. the slight increase or decrease in velocity during hunting season at the distances that are plus side of 1800fps is negligible.

testing ur shit doesn't hurt tho either. the you know, and not guessing off what some retard posted on the internet.

Actually developing a load for it right now with cfe. Have it pretty much dialed in now. Going to run some numbers on my ballistics app and see how much difference there will really be from a hot day to a cold day.

 

[Evintos]

The traditional way of dealing with it is developing both a hot temp load (around 70-80*F) and a cold temp load (around 20-30*F). The loads are usually "good enough" for a +/- 20*F shift. Not really a waste of time, just a lot more data to save for ballistic calculations and you have to remember to bring the right ammo with you.

The other way (new-school?) is finding a load that works across the widest temp range possible that exhibits the least amount of point of impact shift, regardless of SD/ES figures.

 

[MidsouthHunter]

So I just recently performed a powder sensitivity test. The goal was to build my MV TEMP TABLE in my Kestrel 5700. But I figured since I had the chance, I would test 2 powders and get some results.

Powders tested were LEVEREVOLUTION and Gods powder, VARGET. Results were surprising.

These loads were tested in my gun. Use at your own risk. I’m not a scientist. I’m a redneck long range shooter. This post is just information.

Load 1 (COMP):
105 gr Hornady BTHP
HORNADY brass
CCI-41 primer
29.7gr LVR
CBTO: 1.700”

Load 2 (Varmint):
87 gr Hornady VMAX
Resized Hornady 6.5G brass
CCI-41 primer
29.7 gr VARGET
COAL: 2.140”

Test equipment was a magneto V3 chrony, my 20” PROOF 6ARC, and a laser thermometer.

I had 4 different situations I wanted to test. Room temp, cold, frozen, hot. Room temp was ammo sitting in my gun room. 65°. Cold was ammo sitting in the fridge for 12 hrs. 39.5°. Frozen was ammo sitting in my freezer for 12 hrs. 15°. Then hot was ammo sitting in a blanket of hot hands for 30 mins. 90-100°.

Outside temperature was 81° / SP 29.4 / RH 57%

Barrel was fired 3-4x at a moderate rate, (think target engagement like 2-3 sec between) and barrel maintained a 80-85° temp just in front of the barrel nut (outside barrel reading).

I Started with the Varmint load first and alternated between the 2. I would load 3-4 of each round in a mag, run around the back of the house, and shoot over a chrony. Time between removing from environment and shooting was around 45-60 secs. I repeated these steps with room, cold, frozen, and hot in that order. The results certainly surprised me.

The numbers from my test showed that LVR performed better than VARGET. Wwwhhhaaatttt?????

Now I get it, the best case scenario would be 10 rounds from each test. Also shooting in ambient temperatures equal to ammo temperatures. But that’s expensive and even though the temps swing pretty drastic here in the Midsouth in the spring time, the environment was unobtainable this evening. The intent for me in this test was to merely grab my MV, and to build the temp table. Then true BC at what ever environmentals that day and let the kestrel do the rest.

The columns you see for MV are High, Low, AVG. Some shots were 3, some 4. One was only x2 as I had feeding issues. (Varmint loads were for a different rifle)

LVR swung from lowest @ 2708 to Highest @ 2782. Swing of 74°.

VGT swung from lowest @ 2914 to highest @ 3033. Swing of 119°.

Now I’m not getting totally bent out of shape over the temp swing. The most intriguing part is that fact that from 15° to about 75° (75° based off range session MV / TRUEING the week prior), the MV in the COMP load was within 30FPS. Consistently. That speed node for LVR is wide. That’s incredible.

There were some issues as the MV creeped up. I did have a blown primer in the Hot COMP load. I’m not convinced that this was a MAJOR pressure issue as this brass is my “TEST” brass. So she’s been ran hard (maybe 6 firings???). But nonetheless, still to hot. I shouldn’t be getting 2780 in a 20” gasser 6arc. That’s pushing it. The flatten primer has been consistent in loads down to 2650, so not concerned there. Ejector swipes and extractor burrs are my main indicators in this rifle. Those were present.

So take away? 29.7 maybe a little spicy for hot ass summer days/desert/rounds exposed to sun. I personally would back my summer load off to about 29.4-29.5. Then in colder weather, load back up to 29.7. The SD and accuracy are so good at that node that it’s hard to shy away from it. (I found that with LVR, the accuracy node with 105 BTHP Was from 29.6-30.5grs. The increase of velocity was less than 2-3 FPS per grain. So running them a little light in the loafers was no real detriment to performance. Even tough 29.7gr is listed gas gun max, my guess is Hornady saw this speed node as well and directed everyone towards it.).

LVR performed exceptionally well for temperature variations.

Going forward, I will take my temp table I built and true via BC adjustments and see if the data holds. The #1 problem IMHO in long range shooting (when it comes to actual gear/equipment holding you back, not skill level) is bad data. Take the time to ensure at least your zero and drop data are dead nuts. Scope is leveled properly. Those are purely equipment functions. The rest is where a skilled shooter can increase performance.

It would be very efficient if a simple MV test like this can build a useable MV TEMP table that holds true to your load across many environments.

My next question for @Kestrel Ballistics is what are your thoughts on a humidity table?

Again, this is purely hillbilly science and don’t use this method or these loads without proper testing. But hopefully this information may help somebody.

 

[Mike402]

I posted this in the ES vs SD thread, and it certainly applies here as well.

Years ago I was playing around with 180gr Warner Flatlines and CFE 223 with my .308. I was trying to keep it relative vs the 6.5s. I picked out 10 pieces of Lapua brass that were identical in water weight capacity, and bench rest prepped them in every way I could (trim length, annealing with an AMP, flash hole uniforming, etc) I used both OCW and a ladder test to ensure I had the optimal load. When all was said and done I loaded up 10 rounds and fired them over my Magspeed and got this:

It was the most consistent load I had ever come up (even to this day). Groups hovered around 1/4 moa when I drove the gun and managed recoil correctly, all was golden. I had worked them up in ~70ish degree weather. I then went to a long range rifle clinic where the average temp was mid 90s. I was popping primers left and right and accuracy went to complete hell (I'm assuming ES & SD as well) I ultimately had to resort to keeping my ammo in a cooler for the rest of the class, desperately trying to keep them at ~70 degrees. I knew the loads were pretty hot based on the pressure numbers Quickload was spitting out, but I never imagined a 20 degree swing would be so detrimental. Learned a very valuable lesson.
I ultimately shied away from CFE and went to a more vanilla Varget load and have been much happier with the consistency in a broader ranger of conditions and avoidance of temp/pressure spikes.

So it can do wonders, you just have to know what you're getting into.

 

[RegionRat]

Very good lesson. Don't stare at the chrono numbers too hard, they can become a distraction from all the other issues you must master.
Still, that is an impressive 10 shot statistic for any powder, especially CFE223.

 

[Yondering]

So I just recently performed a powder sensitivity test. The goal was to build my MV TEMP TABLE in my Kestrel 5700. But I figured since I had the chance, I would test 2 powders and get some results.

Powders tested were LEVEREVOLUTION and Gods powder, VARGET. Results were surprising.

These loads were tested in my gun. Use at your own risk. I’m not a scientist. I’m a redneck long range shooter. This post is just information.

Load 1 (COMP):
105 gr Hornady BTHP
HORNADY brass
CCI-41 primer
29.7gr LVR
CBTO: 1.700”

Load 2 (Varmint):
87 gr Hornady VMAX
Resized Hornady 6.5G brass
CCI-41 primer
29.7 gr VARGET
COAL: 2.140”

Test equipment was a magneto V3 chrony, my 20” PROOF 6ARC, and a laser thermometer.

View attachment 7862322

I had 4 different situations I wanted to test. Room temp, cold, frozen, hot. Room temp was ammo sitting in my gun room. 65°. Cold was ammo sitting in the fridge for 12 hrs. 39.5°. Frozen was ammo sitting in my freezer for 12 hrs. 15°. Then hot was ammo sitting in a blanket of hot hands for 30 mins. 90-100°.

Outside temperature was 81° / SP 29.4 / RH 57%

Barrel was fired 3-4x at a moderate rate, (think target engagement like 2-3 sec between) and barrel maintained a 80-85° temp just in front of the barrel nut (outside barrel reading).

I Started with the Varmint load first and alternated between the 2. I would load 3-4 of each round in a mag, run around the back of the house, and shoot over a chrony. Time between removing from environment and shooting was around 45-60 secs. I repeated these steps with room, cold, frozen, and hot in that order. The results certainly surprised me.

View attachment 7862360

The numbers from my test showed that LVR performed better than VARGET. Wwwhhhaaatttt?????

Now I get it, the best case scenario would be 10 rounds from each test. Also shooting in ambient temperatures equal to ammo temperatures. But that’s expensive and even though the temps swing pretty drastic here in the Midsouth in the spring time, the environment was unobtainable this evening. The intent for me in this test was to merely grab my MV, and to build the temp table. Then true BC at what ever environmentals that day and let the kestrel do the rest.

The columns you see for MV are High, Low, AVG. Some shots were 3, some 4. One was only x2 as I had feeding issues. (Varmint loads were for a different rifle)

LVR swung from lowest @ 2708 to Highest @ 2782. Swing of 74°.

VGT swung from lowest @ 2914 to highest @ 3033. Swing of 119°.

Now I’m not getting totally bent out of shape over the temp swing. The most intriguing part is that fact that from 15° to about 75° (75° based off range session MV / TRUEING the week prior), the MV in the COMP load was within 30FPS. Consistently. That speed node for LVR is wide. That’s incredible.

There were some issues as the MV creeped up. I did have a blown primer in the Hot COMP load. I’m not convinced that this was a MAJOR pressure issue as this brass is my “TEST” brass. So she’s been ran hard (maybe 6 firings???). But nonetheless, still to hot. I shouldn’t be getting 2780 in a 20” gasser 6arc. That’s pushing it. The flatten primer has been consistent in loads down to 2650, so not concerned there. Ejector swipes and extractor burrs are my main indicators in this rifle. Those were present.

View attachment 7862396

So take away? 29.7 maybe a little spicy for hot ass summer days/desert/rounds exposed to sun. I personally would back my summer load off to about 29.4-29.5. Then in colder weather, load back up to 29.7. The SD and accuracy are so good at that node that it’s hard to shy away from it. (I found that with LVR, the accuracy node with 105 BTHP Was from 29.6-30.5grs. The increase of velocity was less than 2-3 FPS per grain. So running them a little light in the loafers was no real detriment to performance. Even tough 29.7gr is listed gas gun max, my guess is Hornady saw this speed node as well and directed everyone towards it.).

LVR performed exceptionally well for temperature variations.

Going forward, I will take my temp table I built and true via BC adjustments and see if the data holds. The #1 problem IMHO in long range shooting (when it comes to actual gear/equipment holding you back, not skill level) is bad data. Take the time to ensure at least your zero and drop data are dead nuts. Scope is leveled properly. Those are purely equipment functions. The rest is where a skilled shooter can increase performance.

It would be very efficient if a simple MV test like this can build a useable MV TEMP table that holds true to your load across many environments.

My next question for @Kestrel Ballistics is what are your thoughts on a humidity table?

Again, this is purely hillbilly science and don’t use this method or these loads without proper testing. But hopefully this information may help somebody.

Just a comment - you'll get different results if the ammo AND the rifle are at the test temperature (i.e. frozen, hot, etc). That's what you've got in real field hunting conditions, not a hot rifle with frozen ammo.

I'm fortunate to be able to shoot in my yard, so I've tested with the rifle and loaded mag in the deep freezer (-8°F IIRC), cold soaked outside in December (40° F), and the same in warmer temps. I found that while Lever definitely changed velocity in the warmer temps, it leveled off at 40°F and didn't drop any further when frozen. Keep in mind a more comprehensive test with more data points at different temps may likely show this happens somewhere other than 40°, but that's what the coarse resolution of my testing showed for my load in my rifle.

I also think the temp sensitivity is somewhat dependent on the load details, and suspect there may be an optimum load/pressure where sensitivity is fairly low.

I've also observed that when you really are looking for the combination of good accuracy and max velocity with heavy for caliber bullets, nothing beats Lever in the 6mm ARC or other Grendel variants, as well as a bunch of other AR cartridges like 5.56, 20 Tactical, 6.5 Grendel, and even 308.

 

[r.tenorio671]

I've also observed that when you really are looking for the combination of good accuracy and max velocity with heavy for caliber bullets, nothing beats Lever in the 6mm ARC or other Grendel variants, as well as a bunch of other AR cartridges like 5.56, 20 Tactical, 6.5 Grendel, and even 308.

....that's another reference to the use of Lever in 5.56, which has piqued my interest. I can't find any manufacturers published data for it, but I would imagine it closely matches CFE 223, which does have factory data published. I imagine it might boost the 75 BTHP & 77 SMK velocity up in a 16" tube without an extreme pressure build up, but haven't any idea of a good start load to work up from.

Anyone that uses it care to share some data you have used successfully in a gasser?

Edited: I'm not concerned with temp stability, my locale enjoys year-round mid 80's.

 

[SupressYourself]

This is not the direct answer you're looking for, but when trying to figure out Lever charges for a 6.5 Grendel, I observed that in other cartridges where both CFE and Lever were listed together, they were usually within a few tenths of each other. So I used CFE numbers for Lever, started low and worked up, and found a good load right about where I expected it.

 

[Ndbowhunter]

lvr will get you about true best velocity from a 223 that you can possibly get with heavies.. 2.25" and loaded long in bolt guns.

it for sure beats rl-15, h4895, varget, tac, and 8208

can't speak for other powders

 

[r.tenorio671]

...for those responding to my inquiry on using Lever w/556, my thanks. I was pointed to the Johnny's Reloading Bench vids on his MK262 cloning attempt, Lever was one of the powders he tested (vid #8 & vid #11). It was quite informative IMHO.

 

[Ledzep]

I'll echo what Yondering said. Going colder usually has less pressure and velocity drop than going hotter, and there's an elbow in the curve somewhere between 100-140 degrees that things ramp up pretty rapidly.

My approach to it is to try to do load development in the warmest conditions possible. Heating ammo works, too, if you can monitor the temp you keep it at (I'd suggest not going over 120). Start low and work up. Then test the ammo for 10-20 rounds at 90-100 degrees and at 40-60 degrees to get a sensitivity factor.

Hornady 4 DoF has an input field for temp sensitivity factor and baseline temperature and in my experience it handles temp swings very well. I ran LVR in 6 ARC for the first year that I shot it and never had issues in PRS/NRL competitions with elevation issues over a range of temperatures.

Alternatively you can have hot and cold loads... I'd personally rather take the cold temp velocity hit and be able to use my ammo year round. YMMV.

 

[Yondering]

....that's another reference to the use of Lever in 5.56, which has piqued my interest. I can't find any manufacturers published data for it, but I would imagine it closely matches CFE 223, which does have factory data published. I imagine it might boost the 75 BTHP & 77 SMK velocity up in a 16" tube without an extreme pressure build up, but haven't any idea of a good start load to work up from.

Anyone that uses it care to share some data you have used successfully in a gasser?

Edited: I'm not concerned with temp stability, my locale enjoys year-round mid 80's.

I’m out of town and don’t have my data here, but as others said you can start with CFE223 data and go a little heavier from there. I don’t know if any published data for it either, so you’ll have to work up your own load as you see fit. Personally I don’t mind stepping on the throttle a bit, as that’s the whole reason for using Lever anyway, but I back off if primer pockets loosen within 4-5 loads. Off the top of my head, that puts me around 27.8-28.2gr for the 75-77gr bullets, depending on the bullet and the seating depth of course. With my 20” barrel that puts most of these bullets in the mid-2,900’s, although I’m pushing the 75 BTHP a bit over 3,000 with good brass life.

Also as others said, Lever will give you more speed than any other powder within reasonable pressures. Keep in mind though, it also creates more gas than any other 5.56 powder, and at full loads it WILL make your rifle pretty over gassed if it’s tuned to run with 8208 or Varget, etc. If you try my loads above in a rifle tuned for 8208, you’ll see pretty bad swipes and extractor marks, which some guys interpret (wrongly) as high pressure. Get the gas adjustment right though and all that goes away. I keep one rifle tuned for Lever loads, and it won’t even cycle a warm load of 8208 (24.0gr) with the75 BTHP unless it’s suppressed.