6mm ARC Load Data

[AKGuide]

Figured I’d start a thread for the 6mm ARC. Here’s what I have for now.

26” McGowan 1:7” 0.086” gas port, Odinworks adjustable gas block, JP BCG

Using 0.350” insert
Hornady comparator’s headspace 1.183”
Sized 6.5 Grendel Virgin Starline brass headspace 1.187”
Fired cases headspace 1.191”

1.720” CBTO Lands contact 100 TGK & 107 SMK

100 TGK~2.297” OAL
107 SMK~2.287” OAL



12FEB2021 31.6F, 89%H, 30.23inhg
Virgin Starline 1.480”, Rem 7 1/2, CFE223@ 27.5 grs, 107 SMK@ 1.704” CBTO for 0.020” jump and 100 TGK@ 1.707” CBTO for 0.017” seating die set same for both bullets

107-2526, sd10
100-2576, sd11

Loaded five each for barrel break in, velocity test and gas block setting test.

14 clicks for lock back


14FEB2021 33F, 85%H, 29.84inhg
Virgin Starline 1.480”, Rem 7 1/2, CFE223, 107 SMK 1.704” CBTO for 0.020” jump
27.7-2518
27.9-2553
28.1-2558
28.3-2616
28.5-2648
28.7-2635
28.9-2662
29.1-2655
29.3-2699
29.5-2705

15FEB2021 33.6F, 99%H, 29.96inhg
Virgin Starline 1.480”, Rem 7 1/2, [email protected], 107 SMK 1.704” CBTO for 0.020” jump, 100 TGK 1.708” CBTO for 0.016” jump

107-2688avg, sd9
100-2767avg, sd18

 

[LRJammer]

How are you forming your brass from the Starline? What kind of dies are you using?

 

[AKGuide]

I’m using RCBS SB/TC dies and just lubing and running. You will have to trim a bunch. My reformed cases were 1.512” and I modified a lee 6mm PPC case gauge and trimmer to trim to 1.480”.

 

[StaMic006]

What primers are folks using?

 

[LRBuck]

I have used #400s and Br4’s but now I am mostly using #41’s.
The 400s showed some occasional cratering and once a pierced primer with my load (29.6 of Leverevolution). The 41’s seem to be just as, if not more, accurate for me than 400s with no such problems. No issues with the Br4s - just don’t have that many and they are more expensive.

 

[StaMic006]

I have used #400s and Br4’s but now I am mostly using #41’s.
The 400s showed some occasional cratering and once a pierced primer with my load (29.6 of Leverevolution). The 41’s seem to be just as, if not more, accurate for me than 400s with no such problems. No issues with the Br4s - just don’t have that many and they are more expensive.

Thanks for the info. I’m ordering components and needed to know what to look for. I’ve never loaded any small rifle cartridges, only SAUM’s and long action stuff.

What’s your setup? I just built two ARCs. A 12.5” and an 18” so I have a lot of development to do.

 

[LRBuck]

Thanks for the info. I’m ordering components and needed to know what to look for. I’ve never loaded any small rifle cartridges, only SAUM’s and long action stuff.

What’s your setup? I just built two ARCs. A 12.5” and an 18” so I have a lot of development to do.

Sorry for the slow reply.
I have a mostly Aero build with a Rock Creek 22” barrel 1/7 twist that I had spun up from Craddock Precision.
This is the first rifle I have developed a hand load for. Shoots factory ELD m and Black around 2700 and .5-.6 inch groups if I do my part. Took some time to find the best load since I am pretty new at it but once I honed in on 29.5-29.6 grains of LVR with the Berger 109’s, I quit messing with it when I got a .36 group. Figured I would just screw something up. I load them to 2.260, which for this bullet and rifle seems to be the best jump at about .060. Hornady brass.
When it is warm (over 85 deg) I go with 29.5. Cooler, 29.6. Seems to me to shoot better/more consistently if I keep the speed range between 2690-2760 or so.
I like shooting distance with it - out to 1200 so far. When I have the chance, I am going to try for the mile.

 

[Mopar man]

any one trying sw precision powder yet

 

[trdjohn]

found this link recently, there is mention of SW precision for bolt gun near end of article, apparently the author looked at 6 mm BR data and worked up load from there, maybe using QL too?

https://www.handloadermagazine.com/6mm-arc

 

[AKGuide]

Shot this group with hornady black 105’s today in 5 degrees and howling wind. They are 0.2 mils lower than my 100 TGK handloads. I was holding on the left side of the marker dot at 100 yards. So hopefully when it warms up and the wind subsides I will see if I can repeat this group. The other rounds were in the pic were from a clean barrel and also the wind was gusting hard. The last five were when the wind was consistent.

 

[creepbam]

18” Proof AR.
95 Berger VLD Hybrid
CFE 223 28.8 and 29.4.
2.25” COAL
LabRadar was not cooperative with me at the range so velocity is unknown.

 

[ARShooter91]

Any idea how far they're jumping? I just bought 800-95s to hopefully find a load for my 1:8 Seekins barrel. Those 95s moving fast keep up with 108g ELD with drift and a good bit less drop if you assume a decent starting velocity

 

[creepbam]

No idea honestly. I just loaded them to 2.25 COAL to be mag friendly.

 

[Rylo]

Anyone loading for a gas gun in ARC? I'm curious if anyone is having success without crimping.

 

[creepbam]

The loads I posted above were in a AR. Not crimped either.

 

[Rylo]

The loads I posted above were in a AR. Not crimped either.

Ok great!! Thank you

 

[Dogtown]

I’ll throw my initial pressure testing data into the ring.

26” Bartlein 1:7.25 AR15 Rifle +2 gas

All loads were using resized Lapua 6.5 Grendel brass, GM205MAR primers, and loaded to 2.26" COAL

No pressure signs in any of these loads, so clearly they can be pushed a bit harder.

110 A-Tip
RL17
26.6gr-29.0gr
2287-2501fps

110 A-Tip
Varget
24gr-26.2gr
2330-2557fps

95 VLD TGT
ARComp
24gr-26.4gr
2542-2782fps

95 VLD TGT
N140
25gr-27.4gr
2382-2601fps

I’m going to push the Varget and ARComp a bit harder and test LVR as well.

 

[ARShooter91]

My 95s just came in and at 2.25oal I'm at 100 thousandths jump. No plans to crimp. I don't with my 6.5 Grendel and never an issue.

 

[LRBuck]

Anyone loading for a gas gun in ARC? I'm curious if anyone is having success without crimping.

My load above (#5 and7) is gas gun. Not crimped.

 

[Rylo]

My load above (#5 and7) is gas gun. Not crimped.

Thank you!! I really didn’t want to crimp. Never crimped on bolt load but I’ve also never done gas loads before

 

[Dogtown]

Hey guys, is there something special about Hodgdon LVR in 6ARC? Because I just got back from the range and saw something I've never seen before.

I was continuing to do some pressure testing with 110 A-Tips out of a 26" gas gun. Last week it was Varget and RL17; today it was pushing Varget a bit harder, some TAC just to see how it does, and LVR. With pressure testing I just load single rounds with a powder ladder but still shoot each string into its own POA, even though I'm not expecting groups.

Yep, Varget continues to be in the velocity zone I expected with this setup:
26 - 27.4 gr
2516 - 2643 fps

and TAC wasn't a slouch either, but I did see pressure on the final round:
26 - 27.8 gr
2475 - 2656 fps

but holy shit all of my LVR rounds were touching!
26 - 27.8gr
2386 - 2577 fps

In my ~20 years of reloading, I've never seen a roughly 10 round pressure ladder result in an amazing group. Either this stuff is ideal for this cartridge/bullet combo or that's just the most powder charge tolerant load I've ever seen?

 

[JFR]

Tagging in!

 

[Dogtown]

Not a fan of that “watch” button in the upper right of threads?

 

[357Max]

Hey guys, is there something special about Hodgdon LVR in 6ARC? Because I just got back from the range and saw something I've never seen before.

I was continuing to do some pressure testing with 110 A-Tips out of a 26" gas gun. Last week it was Varget and RL17; today it was pushing Varget a bit harder, some TAC just to see how it does, and LVR. With pressure testing I just load single rounds with a powder ladder but still shoot each string into its own POA, even though I'm not expecting groups.

Yep, Varget continues to be in the velocity zone I expected with this setup:
26 - 27.4 gr
2516 - 2643 fps

and TAC wasn't a slouch either, but I did see pressure on the final round:
26 - 27.8 gr
2475 - 2656 fps

but holy shit all of my LVR rounds were touching!
26 - 27.8gr
2386 - 2577 fps

In my ~20 years of reloading, I've never seen a roughly 10 round pressure ladder result in an amazing group. Either this stuff is ideal for this cartridge/bullet combo or that's just the most powder charge tolerant load I've ever seen?

Welcome to the LEVER party!

Lever is to these small cases, like RL26 is to the Creedmoor.

Same goes for 224 Valk + Lever.

Your Lever loads are super mild.
mine is a 22" Bartlain + 2" gas Craddock

Edit to add:
All the loads posted below were shot in 95 degree temp. I worked them up in cooler weather & wanted to check them again in the heat.

Using Lapua brass, last time out with the 95VLD's loaded @2.270 with 30.7 Lever were 2933

Hornady published 29.7 max load for Lever with 110's
Load another Lever ladder starting @27.8 - 29.? Caution, once you pass 29.0gr Lever you'll become addicted.

In mine with 29.8 Lever & Berger 109LRHT @2.290 = 2732
29.8 with Hornady 108's @2.290 = 2778
30.0 with 105 Berger Hyb @2.270 = 2782
30.5 with Sierra 100TGK @ 2.255 = 2846

What you'll find with Lever is that it SD's start to tighten in the upper end loads. It also tends to shoot better when pushed. Unlike 8208, RL15.5, Vit N135 etc. Lever does not pressure spike when you push the loads. I haven't experienced the high temp sensitivity claimed with Lever in these small cases YMMV. It's got some temp sensitivity sure, but not nearly what I was expecting.

 

[Dogtown]

Very interesting. I just loaded up another ladder to 28.4, but sounds like I should go back in the garage and add some more up to 29ish 30ish.

I really hope yesterday’s experience with that LVR ladder shooting 1/2” wasn’t a fluke. I’ve just never seen anything like that before. In fact I already loaded two 10-shot strings to test with 27.6 & 27.8 thinking if they shot 1/2” as well then I’d be done, even though I was hoping to get 110s closer to 2700fps out of a 26” barrel.

 

[JFR]

Not a fan of that “watch” button in the upper right of threads?

So, I'm fucking dumb. OK?

 

[JFR]

Welcome to the LEVER party!

Lever is to these small cases, like RL26 is to the Creedmoor.

Same goes for 224 Valk + Lever.

Your Lever loads are super mild.
mine is a 22" Bartlain + 2" gas Craddock

Edit to add:
All the loads posted below were shot in 95 degree temp. I worked them up in cooler weather & wanted to check them again in the heat.

Using Lapua brass, last time out with the 95VLD's loaded @2.270 with 30.7 Lever were 2933

Hornady published 29.7 max load for Lever with 110's
Load another Lever ladder starting @27.8 - 29.? Caution, once you pass 29.0gr Lever you'll become addicted.

In mine with 29.8 Lever & Berger 109LRHT @2.290 = 2732
29.8 with Hornady 108's @2.290 = 2778
30.0 with 105 Berger Hyb @2.270 = 2782
30.5 with Sierra 100TGK @ 2.255 = 2846

What you'll find with Lever is that it SD's start to tighten in the upper end loads. It also tends to shoot better when pushed. Unlike 8208, RL15.5, Vit N135 etc. Lever does not pressure spike when you push the loads. I haven't experienced the high temp sensitivity claimed with Lever in these small cases YMMV. It's got some temp sensitivity sure, but not nearly what I was expecting.

Thank you for this. I was shying away from the Lever train because of temp sensitivity claims. The small case variable, I had not thought of...

JFR

 

[db2000]

Very interesting. I just loaded up another ladder to 28.4, but sounds like I should go back in the garage and add some more up to 29ish 30ish.

I really hope yesterday’s experience with that LVR ladder shooting 1/2” wasn’t a fluke. I’ve just never seen anything like that before. In fact I already loaded two 10-shot strings to test with 27.6 & 27.8 thinking if they shot 1/2” as well then I’d be done, even though I was hoping to get 110s closer to 2700fps out of a 26” barrel.

Lots of reports like this. I was able to get 4# same lot so pretty excited about that. Will report back in a couple weeks when the gun is built. 18” AR so will be a little slower. There’s some temp instability is the drawback to LVR I believe.

 

[ARShooter91]

I remember seeing a test here where a guy shot 15degrees, room temp, and then 95degrees(approx. my memory could be a little off)with a Lever load and a Varget load. The Varget load had more spread than Lever.

 

[db2000]

I remember seeing a test here where a guy shot 15degrees, room temp, and then 95degrees(approx. my memory could be a little off)with a Lever load and a Varget load. The Varget load had more spread than Lever.

Yeah, I saw that post. Also another where the guy says he hasn’t seen big temp swings. I hope it’s stable in my gun. Only one way to find out!

 

[Dogtown]

Well shit, you guys and yesterday’s target helped convince me: 8 pounds of LVR ordered!

 

[db2000]

Well shit, you guys and yesterday’s target helped convince me: 8 pounds of LVR ordered!

Cool! Thanks for the heads up!
Interesting they’re charging $36 hazmat

 

[Dogtown]

Yeah, his hazmat charges fluctuate, but $230 for 8lbs is about that much cheaper than the next best I could find, so it works out I figured.

 

[db2000]

Yeah, his hazmat charges fluctuate, but $230 for 8lbs is about that much cheaper than the next best I could find, so it works out I figured.

Definitely. H4350 was $400 all in from PV recently. Happy to have gotten it regardless.

 

[ARShooter91]

Yeah, I saw that post. Also another where the guy says he hasn’t seen big temp swings. I hope it’s stable in my gun. Only one way to find out!

I can vouch it definitely likes to be near max. I have a load that's looking very promising with the 95g VLD. Too hot for a summer load so I'll back it off a bit and keep some loaded to try in different temps.

 

[hertz654]

Good news for reloaders from Peterson Cartridge Company; their new quarterly journal yesterday mentioned development of 6mm ARC brass in 2023.

 

[ARShooter91]

I'll update with full Chrono readings but 48deg. I averaged 2889fps with 95g VLD and yesterday 2905fps at 69deg. 31.2g LVL. Seeing some pressure signs and maybe a little overgassed at near 70degrees, probably a load for freezing temps. Accuracy is there from 30.8g-31.4g

 

[ARShooter91]

31.2g LVL 95g Berger VLD Target

2904, 2904, 2911, 2911, 2898
68degrees 48% humidity 14:30

2892, 2886, 2898, 2886, 2898, 2873
48degrees 56% humidity 13:00

2807, 2812, 2812, 2812, 2783, 2807, 2824 22degrees 78% humidity 8:00

So ES and group opened up at 22*. I'll shoot again today while it's warmer to check accuracy. I'll have to check my book for details, I did see excellent accuracy with 31g but don't remember temps.

Also want to redo velocity and check my book as I thought I was seeing more velocity in the 20s. That's when I started initial load development.

 

[357Max]

31.2g LVL 95g Berger VLD Target

2904, 2904, 2911, 2911, 2898
68degrees 48% humidity 14:30

2892, 2886, 2898, 2886, 2898, 2873
48degrees 56% humidity 13:00

2807, 2812, 2812, 2812, 2783, 2807, 2824 22degrees 78% humidity 8:00

So ES and group opened up at 22*. I'll shoot again today while it's warmer to check accuracy. I'll have to check my book for details, I did see excellent accuracy with 31g but don't remember temps.

Also want to redo velocity and check my book as I thought I was seeing more velocity in the 20s. That's when I started initial load development.

Good info.
Question: was the barrel new when you started at 22 degrees?? They do speed up over the first 150 - 200 rounds.
I always run 5 factory loads over the chrono as a control if under 200 rnds to account for barrel speed up.

 

[ARShooter91]

Good info.
Question: was the barrel new when you started at 22 degrees?? They do speed up over the first 150 - 200 rounds.
I always run 5 factory loads over the chrono as a control if under 200 rnds to account for barrel speed up.

This is a Seekins DMR 22in that I bought off a consignment rack. Barrel extension and muzzle/brake were pretty clean. I'd guess only 20-50rds on it and I shot 140rds of factory before I started any load developement.

 

[ARShooter91]

Shot another group at 100m yesterday. 3 shots touching and a couple wild ones. I think it may need cleaned. Lever that dirty? 50 shots and accuracy goes to crap

Edit: Wow, yeah let it soak for half hour with Hopps oil. Patches were dark dark. Ran some clean through, mopped out the chamber and accuracy was back.

 

[Dogtown]

So you guys weren't kidding. LVR SDs really start to drop as you get into the 30gr zone. This morning I tested out 29.5gr, 30gr & 30.5gr and all had low single digit SDs and not-bad-for-a-gas-gun groups. This is 110 A-Tips loaded at 2.26" COAL - not sure how much I can tweak seating depth with this combo, but I'll try. If anything, the performance combined with really low recoil tells me it's time to build a bolt gun as well.

Also, the suggestion to try E-Lander mags solved some finicky feed issues I was having.

 

[Dogtown]

I'm starting to think QL's burn rate for LVR must be off. I tested some more 110 A-Tip loads, shooting 10-shot strings of 29.7, 30.2 & 30.7gr charge weights at 2.26"

Still no pressure, but it was getting really compressed with 30.7gr. QL says I should be way out of bounds with these, but yet I'm not. No flattened primers, no ejector marks, etc. On top of that, even out of a 26" barrel I'm not getting the velocities I'd expect (ex 30.7gr @ 2731fps avg). There's now 124 rounds through this barrel, so there's still a chance I'll see a speed-up soon, but it still feels kind of odd.

That said, groups were pretty nice and SDs were low-to-mid single digits, so this is clearly the powder.

 

[CWik]

Hey guys, is there something special about Hodgdon LVR in 6ARC? Because I just got back from the range and saw something I've never seen before.

I was continuing to do some pressure testing with 110 A-Tips out of a 26" gas gun. Last week it was Varget and RL17; today it was pushing Varget a bit harder, some TAC just to see how it does, and LVR. With pressure testing I just load single rounds with a powder ladder but still shoot each string into its own POA, even though I'm not expecting groups.

Yep, Varget continues to be in the velocity zone I expected with this setup:
26 - 27.4 gr
2516 - 2643 fps

and TAC wasn't a slouch either, but I did see pressure on the final round:
26 - 27.8 gr
2475 - 2656 fps

but holy shit all of my LVR rounds were touching!
26 - 27.8gr
2386 - 2577 fps

In my ~20 years of reloading, I've never seen a roughly 10 round pressure ladder result in an amazing group. Either this stuff is ideal for this cartridge/bullet combo or that's just the most powder charge tolerant load I've ever seen?

@Dogtown – Any issues with the 27.4 gr of Varget loads? I'm on the Lever train as well, but wanting to load up some Varget around that charge (with Berger 109s) to see how they do. Wondering if you ran into any pressure signs, etc. at 27.4

 

[Dogtown]

Nah, no pressure at 27.4gr of Varget.

 

[ARShooter91]

Anyone getting decent velocity with Varget and lighter bullets? 90-100g. My Lever loads have produced some of the best groups and by far the best ES and SDs I've ever had. Buuut it is so stinking dirty suppressed. Not a big issue except carbon/powder fouling starts causing fliers faster than anything I've had before.

 

[SouthFLShootin]

Just got a 20" proof stainless barrel and I have been very happy with it it.

The barrel has maybe 100 rounds on it and it shoots the 103 gr eldx consistently sub MOA, usually around .5"

Once i had some spent brass, I tried some Hornady 80gr CX monolithics over CFE223 and found a really sweet spot at 31grs of powder and 2.095" COAL. Velocity was 2940-2950 10' out using one of those old style chronographs.

Going to see how it works on hogs as soon as I get a chance.

 

[White Mamba]

27.8 and 28g Varget w/108 eld, 2700fps
Mirrors factory speed and accuracy

 

[SouthFLShootin]

Finally had the chance to run my 20" proof barrel with factory Hornady ELDX ammo and also some hand loaded 87gr VMAX out to 1000 yards.

I'm super excited about this rifle. It is way more capable than I was expecting. The 87gr vmax holds the same dope as my GT out to almost 500 yards. The 103s are just stupid accurate inside 700 yards. Makes me question even trying to hand load 103s, but I think I can squeeze some more velocity out of them with LVR.

I'm actually so impressed, I want to build another one with a 14.5" barrel and run a dedicated can on it.

Anyone have any velocity data with a 14.5"? I have done quite a bit of looking and have only found a graph of what factory Hornady match ammo ran at different lengths.

 

[Dogtown]

Anyone have any velocity data with a 14.5"? I have done quite a bit of looking and have only found a graph of what factory Hornady match ammo ran at different lengths.

Not specifically, but here's a ballpark of what kind of velocities QL predicts using 103s with LVR

I too am super impressed with 6ARC and ready to do the same.