6mm ARC loads with Temp Stable Powders

[SMTGWKD]

Had a bad run with temp sensitive powder loads and PRS (never leave a mag in the sun, period) and have stuck to temp stable powders for all loadings since.

Wondering if anyone has found a sweetspot for their gas gun with Varget, xbr8208, etc.

Preliminary testing in my 18" proof give the following as promising - less velocity as compared to Factory or CFE and Lever, but still great ballistically.

Hornady Brass
CCI 450
108 ELD-M
26.7 Varget
Mag length load
2513 fps at 48 degrees farenheit

Same as above but
25.0 xbr8208
2450 fps at 28 degrees farenheit

Same as above but
105 BTHP
26.7 Varget
2542 fps at 48 degrees farenheit

For reference, factory 105 Black ran 2560 and factory 108 Match ran 2580 the same day (28 degrees).

 

[sprad05]

Any updates here, I just tried AR-COMP with 103 vapor trails 26.6gr was 2618. Was starting to have light smears and next load up primer was starting to look really sketchy. I have Varget and 8208xbr, so debating which of the 3 would be best.

I'm also worried about temp stability

 

[Olen_4504]

geez. my 21" barrel shoots both the 105g and 108g factory ammo at 2670 (50-60 degrees)

when I decide to load for it, I'm going to try h4895 and a 75-85g bullet for critters

 

[SMTGWKD]

Any updates here, I just tried AR-COMP with 103 vapor trails 26.6gr was 2618. Was starting to have light smears and next load up primer was starting to look really sketchy. I have Varget and 8208xbr, so debating which of the 3 would be best.

I'm also worried about temp stability

If you have an 18" barrel, I'd download for sure.

xbr8208 worked great with 58 Vmax at 30.4-30.7 and gave top velocity average of 3,163 fps with .487" group average.

At present, I'm loading Varget for heavies and xbr8208 with lights in 6 ARC.

 

[shortround91]

I use H4895 for Barnes Varminators 58grainers 29.8gr OAL 2.045 from my Oden 20plus 1 get some pretty damn good accuracy and 3300fps velocities

 

[Hoser]

I am using H4895 in my 6 Grendel and am really happy with the accuracy.

 

[TainoPatriot]

Had a bad run with temp sensitive powder loads and PRS (never leave a mag in the sun, period) and have stuck to temp stable powders for all loadings since.

Wondering if anyone has found a sweetspot for their gas gun with Varget, xbr8208, etc.

Preliminary testing in my 18" proof give the following as promising - less velocity as compared to Factory or CFE and Lever, but still great ballistically.

Hornady Brass
CCI 450
108 ELD-M
26.7 Varget
Mag length load
2513 fps at 48 degrees farenheit

Same as above but
25.0 xbr8208
2450 fps at 28 degrees farenheit

Same as above but
105 BTHP
26.7 Varget
2542 fps at 48 degrees farenheit

For reference, factory 105 Black ran 2560 and factory 108 Match ran 2580 the same day (28 degrees).

Although I haven't shot or developed loads for my new 6mm ARC, I do find Interesting the amoint of powder you are using. In my .223 loads I use 26.0 of Varget and 24.5 to 25.0 of xbr. Isint case capacity for 6mm is around 29-30?

 

[shortround91]

I’ve pretty much settled on LEVERolution for my 6ARC loads from 100-115 grain. Super consistent outstanding velocity and accurate as hell. I’ve done extensive testing currently
loading this and I have load data with Chronograph’d data to back it up if I could help with any other loads hit me up more than happy to help
Bill
6ARC Nosler RFD 115gr
LEVERolution 29.0gr smrp CCI OAL 2.253

 

[shortround91]

I’ve pretty much settled on LEVERolution for my 6ARC loads from 100-115 grain. Super consistent outstanding velocity and accurate as hell. I’ve done extensive testing currently
loading this and I have load data with Chronograph’d data to back it up if I could help with any other loads hit me up more than happy to help
Bill
6ARC Nosler RFD 115gr
LEVERolution 29.0gr smrp CCI OAL 2.253
View attachment 7964687

 

[ranger0787]

After noticing that the Hornady line uses temp-sensitive powders, I tried developing a load yesterday with Varget. I initially didn't want to use it due to QL showing the MV would be pretty low. I thought it may be better to have consistency over MV. The below results were shot at 100yds in the prone with Harris bipod and rear squeeze bag. Rifle specs are: JP Enterprises thermal-fit upper with 20" Compass Lake Engineering-chambered Criterion 6 ARC barrel which I asked them to set up for the 108gr ELD-M bullet. Daniel Defense DDM4V7 lower with TriggerTech AR trigger set at 4.5 pounds and Magpul PRS stock. Scope was a March 1.5-15x42 with MTR-4 reticle. Rifle weighs in complete at 14 pounds.
The factory Hornady 108gr ELD-M wouldn't initially shoot here in SoFla, so I took everything with me to Virginia. The temps were between 32-58F and both the ELD-M and the Hornady Black 105gr BTHP shot very well; largest groups were @ .750, smallest were @ .450 for 5 shots. Brought everything back to SoFla and the groups opened up again. So...On to Varget. I'll reload 26.2 through 26.9 in .10gr increments and see if I can spot the tightest of all. Then maybe play around with seating depths.

 

[MountainHombre]

After noticing that the Hornady line uses temp-sensitive powders, I tried developing a load yesterday with Varget. I initially didn't want to use it due to QL showing the MV would be pretty low. I thought it may be better to have consistency over MV. The below results were shot at 100yds in the prone with Harris bipod and rear squeeze bag. Rifle specs are: JP Enterprises thermal-fit upper with 20" Compass Lake Engineering-chambered Criterion 6 ARC barrel which I asked them to set up for the 108gr ELD-M bullet. Daniel Defense DDM4V7 lower with TriggerTech AR trigger set at 4.5 pounds and Magpul PRS stock. Scope was a March 1.5-15x42 with MTR-4 reticle. Rifle weighs in complete at 14 pounds.
The factory Hornady 108gr ELD-M wouldn't initially shoot here in SoFla, so I took everything with me to Virginia. The temps were between 32-58F and both the ELD-M and the Hornady Black 105gr BTHP shot very well; largest groups were @ .750, smallest were @ .450 for 5 shots. Brought everything back to SoFla and the groups opened up again. So...On to Varget. I'll reload 26.2 through 26.9 in .10gr increments and see if I can spot the tightest of all. Then maybe play around with seating depths.

View attachment 8292071

Great data. Makes me want to take another look at Varget. I use Varget for more calibers and loads than anything else and keep a few 8 lb jugs on hand.

I don't think anyone considers 2520 to be temp stable, but for now that's what I have settled on for 6 ARC and .308. I've tried Varget, Lever, CFE223, TAC, and a couple others in 6 ARC with lesser results. Here's my best load so far-

6mm ARC, Berger 105 BT Target, 29.0 gn 2520 ** (essentially same results w/ 105 Hybrids)
24" Bartlein Barrel AR15
Series 24 Shots: 5
Min 2735 Max 2746
Avg 2739 S-D 4.8
ES 11

** Note that 29.0 is well within Accurate/Hodgdon limits but slightly exceeds Hornady 'semi' load data. Don't assume this is OK in your AR. I'm running a JP high pressure bolt and there are zero signs of pressure. Brass is holding up to several reloads on the same case w/ annealing before resizing.

I've seen a lot of traffic on the interwebs making negative claims about 2520 including temperature sensitivity, but I say let them keep jabbering- more for me. Some anecdotes why I think this:

Couple days ago in 20-degree weather I shot .382 to .436 MOA groups at 100 yards once the barrel was warm. Cold bore group size was .477 MOA. Does similar in summer weather. The finer granules of 2520 are much easier for me to meter accurately than is Varget. POI not changing from cold to warm barrel.

2520 for .308 did very well for me in brutal Camp Perry heat at the Nationals a couple years ago. With a self built Bula M14 I shot a clean stage in slow prone and a 98/100 in rapids. I could have dropped a few points in offhand and still won but apparently I'm not particularly temp stable and could only grab bronze . Sunny, ~102 degrees, and typical nasty humidity. After slow prone the barrel was already blazing hot and I'm sure the chamber was getting pretty warm.

I do keep my mags out of the sun, but I think the OP does that as well based on his post.

 

[Fatelvis]

Great data. Makes me want to take another look at Varget. I use Varget for more calibers and loads than anything else and keep a few 8 lb jugs on hand.

I don't think anyone considers 2520 to be temp stable, but for now that's what I have settled on for 6 ARC and .308. I've tried Varget, Lever, CFE223, TAC, and a couple others in 6 ARC with lesser results. Here's my best load so far-

6mm ARC, Berger 105 BT Target, 29.0 gn 2520 ** (essentially same results w/ 105 Hybrids)
24" Bartlein Barrel AR15
Series 24 Shots: 5
Min 2735 Max 2746
Avg 2739 S-D 4.8
ES 11

** Note that 29.0 is well within Accurate/Hodgdon limits but slightly exceeds Hornady 'semi' load data. Don't assume this is OK in your AR. I'm running a JP high pressure bolt and there are zero signs of pressure. Brass is holding up to several reloads on the same case w/ annealing before resizing.

I've seen a lot of traffic on the interwebs making negative claims about 2520 including temperature sensitivity, but I say let them keep jabbering- more for me. Some anecdotes why I think this:

Couple days ago in 20-degree weather I shot .382 to .436 MOA groups at 100 yards once the barrel was warm. Cold bore group size was .477 MOA. Does similar in summer weather. The finer granules of 2520 are much easier for me to meter accurately than is Varget. POI not changing from cold to warm barrel.

2520 for .308 did very well for me in brutal Camp Perry heat at the Nationals a couple years ago. With a self built Bula M14 I shot a clean stage in slow prone and a 98/100 in rapids. I could have dropped a few points in offhand and still won but apparently I'm not particularly temp stable and could only grab bronze . Sunny, ~102 degrees, and typical nasty humidity. After slow prone the barrel was already blazing hot and I'm sure the chamber was getting pretty warm.

I do keep my mags out of the sun, but I think the OP does that as well based on his post.

Thanks for the data. Did you load the 6ARC using 2520 to 2.26" OAL?

 

[Kocher]

26.9 varget looks to be good to go?
I have started to load work up varget and 87vmax and 80eldvt

Do you all think varget is good or too slow? For that bullet combo

 

[supercorndogs]

I shot varget with 90-105g bullets. I have since switched to mp501 which is supposed be like 2520. I have some lever for when that's gone. I like ball powders for speed. They work great in a volume thrower. Really speeds the process over weighing each charge.

 

[Kocher]

Well, when I went shooting the six arc today, Varget just couldn’t hang with the ball powders. My barrel on the other hand is going need to be sent back to Craddock… send over100plus down the tube..not good.

A good barrel will group, even if you have different fps…this one has shot bad from day one…

Revolution pushed the 87gr vmax 3,000fps.
Impressive! Speed…. Can’t comment on accuracy as there is something not right with it.

 

[MarshallDodge]

I'm hearing some good things about Vihtavouri N133 in the 6ARC.

In 223, my choice was 8208XBR, but am starting to see good results with N133 as a substitute.