6 ARC Gas Guns

[steve101610]

Looking to start a 6 ARC gas gun load page. Post as much info as you can. I will start.
18” craddock 7 twist
58gr vmax .010 off lands
30.3gr of benchmark
CCI 450 and Hornady brass
3280 fps with single digit sd and consistent 3/4 moa.
Going to start playing with 105 hybrids and varget. These will be jumping about .130 to fit in the mag.

 

[db2000]

There’s plenty of pages already. A2230 is your friend.

Seekins AR Shaw 18” SS 1:7.5”
Magnetospeed V3

7/16/23
84F 56% 29.88 in

Hornady 58 gr VMAX
A2230 32.5
Hornady brass x 5
205M FGMM
BTO 1.6650
COL 1.4900
3501, 3494, 3496, 3486, 3503 SD 6.6 1” (4 were 0.5”) mild pressure
3501, 3494, 3496, 3486, 3503,
3500, 3512, 3505, 3496, 3518 SD 9.1 1.4” (6 were 0.7”)

32.5 gr A2230
3508, 3525, 3504, 3506, 3496
3532, 3510, 3522, 3513, 3513 SD 10.7 1.5” (7 were 1”)

 

[rlsmith1]

Anyone have a starting point for 75gr VMAX's? I'm mostly curious where I should set my BTO to have the best chance at success. I do have 65gr and 87gr flavors as well but would prefer to stick with the 75's as they will let me use up the pile of TAC I have sitting around.

@db2000 if there are pages of 6 ARC load data on here I'm missing it.

Thanks!

 

[Dogtown]

Running some experiments with powders that aren't LVR out of a 16" Proof carbon.

103 ELD-X
Starline Brass
GM205MAR
2.245" COAL

26.5gr N540
25.8gr TAC
Both shooting around 2350fps with low SD/ES

 

[db2000]

Anyone have a starting point for 75gr VMAX's? I'm mostly curious where I should set my BTO to have the best chance at success. I do have 65gr and 87gr flavors as well but would prefer to stick with the 75's as they will let me use up the pile of TAC I have sitting around.

@db2000 if there are pages of 6 ARC load data on here I'm missing it.

Thanks!

It might be in a different 6 ARC thread but they’re around.

 

[rlsmith1]

It might be in a different 6 ARC thread but they’re around.

If you stumble across it tag ya boi please

 

[AKGuide]

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

17FEB2021 34F, 99%H, 29.85inhg
Virgin Starline 1.480”, Rem 7 1/2, [email protected], 107 [email protected]” CBTO for 0.010” jump
2721avg, sd5; 0.85” 5-shot group

21MAR2021 27F, 86%H, 30.09inhg
Virgin Starline 1.480”, Rem 7 1/2, [email protected], 100 [email protected]” CBTO for 0.010” jump
29.0-2717avg, sd22
H4895 w/ GM205MAR 25.8-2718avg, sd4

 

[rlsmith1]

18" Proof ss barrel (rifle +1 gas)

Once fired Hornady brass 1.485" length
Winchester primers
30.0g of TAC
75 VMAX
1.670" BTO
~1MOA
Did not chrono, but should be between 2950fps and 3000fps

 

[padom]

We will make this the 6 ARC dedicated all things AR thread. Loads, equipment, etc.

 

[padom]

I wanted something new to play with in the AR world. I've resisted but said WTH lets play with 6 ARC and see how it does.

Heres what I decided to build. Had almost all these parts laying around. Got the barrel for under $350 and had to grab a RCA 6.5 Grendel bolt. I already had a RCA 5.56 BCG new sitting in a box.

22" Rainier Ultramatch MOD2 6 ARC +2 Gas
Rubber City Armory BCG with AGK
MEGA Billet AMBI lower
MEGA SBU Thick Walled Billet Upper Receiver
Geissele Super Braided 42 and H1 Buffer
Geissele Premium Mil-Spec Buffer Tube
LaRue Tactical MBT-2S Straight Bow Trigger w/JP Spring
Battle Arms Development Ambi Safety
Magpul PRS Lite
250pcs Starline brass

Just deciding on what handguard. May go with a JP but still deciding.


I would like to run lighter bullets fast and lights out accurate in the 60-80gr range but we will see what this barrel likes.

 

[357Max]

I wanted something new to play with in the AR world. I've resisted but said WTH lets play with 6 ARC and see how it does.

Heres what I decided to build. Had almost all these parts laying around. Got the barrel for under $350 and had to grab a RCA 6.5 Grendel bolt. I already had a RCA 5.56 BCG new sitting in a box.

22" Rainier Ultramatch MOD2 6 ARC +2 Gas
Rubber City Armory BCG with AGK
MEGA Billet AMBI lower
MEGA SBU Thick Walled Billet Upper Receiver
Geissele Super Braided 42 and H1 Buffer
Geissele Premium Mil-Spec Buffer Tube
LaRue Tactical MBT-2S Straight Bow Trigger w/JP Spring
Battle Arms Development Ambi Safety
Magpul PRS Lite
250pcs Starline brass

Just deciding on what handguard. May go with a JP but still deciding.


I would like to run lighter bullets fast and lights out accurate in the 60-80gr range but we will see what this barrel likes.

Keep a very close eye on that POS TIN coated barrel extension. My first 22" UM grew .015 headspace in under 400 rounds. All wear was on the extension lugs. Told them to check hardness, but I'd bet they didn't. My replacement barrel now has 90 rounds on it and it looks like it's gained about .003 HS so far.

 

[357Max]

@rlsmith1 - Here is a link to the big 6ARC thread. Tons of load data in there.

New 6mm Advanced Rifle Cartridge

I hadn't seen this posted here yet, but SAAMI added a 6mm Grendel derivative called the 6mm Advanced Rifle Cartridge or 6mm ARC to their newly accepted cartridges list. 6mm ARC introduction pdf The case looks like the shoulder has been moved back, and the neck is a little shorter as compared...

www.snipershide.com

 

[357Max]

@padom - I'm not the only one that has had lug set back with the Rainier. Here is a link showing the carnage on mine.

https://www.snipershide.com/shootin...tch-ar-15-barrel-damage.7209296/post-11444788

 

[padom]

@rlsmith1 - Here is a link to the big 6ARC thread. Tons of load data in there.

New 6mm Advanced Rifle Cartridge

I hadn't seen this posted here yet, but SAAMI added a 6mm Grendel derivative called the 6mm Advanced Rifle Cartridge or 6mm ARC to their newly accepted cartridges list. 6mm ARC introduction pdf The case looks like the shoulder has been moved back, and the neck is a little shorter as compared...

www.snipershide.com

Thanks, I just stickied it. I couldnt find it but I see its because ARC is spelled out. I just stickied it.

 

[padom]

Keep a very close eye on that POS TIN coated barrel extension. My first 22" UM grew .015 headspace in under 400 rounds. All wear was on the extension lugs. Told them to check hardness, but I'd bet they didn't. My replacement barrel now has 90 rounds on it and it looks like it's gained about .003 HS so far.

Interesting. I will for sure. And for good measure, Ill shoot an email off to my contacts over at Rainier and let them know Ill be keeping a close eye on this possible issue in my testing. I know who does their barrels also. Very high end well known shop constantly mentioned here on the hide...

 

[357Max]

Interesting. I will for sure. And for good measure, Ill shoot an email off to my contacts over at Rainier and let them know Ill be keeping a close eye on this possible issue in my testing. I know who does their barrels also. Very high end well known shop constantly mentioned here on the hide...

Yeah I suspect that well known shop doesn't supply the Tin extensions.

I'll be curious to see if yours has the same issue. Hope it doesn't for your sake.

From what I'm seeing this barrel will be going back also. They should have listened the first time when I told them these extensions were soft.

 

[padom]

Yeah I suspect that well known shop doesn't supply the Tin extensions.

I'll be curious to see if yours has the same issue. Hope it doesn't for your sake.

From what I'm seeing this barrel will be going back also. They should have listened the first time when I told them these extensions were soft.

How the accuracy

 

[357Max]

How the accuracy

Decent, not stellar. Just under 1 moa with 108's, berger 109 & 105's were better. I'm about to order the 22" RTR. I'm sick of chasing the lugs lol.

 

[supercorndogs]

Yeah I suspect that well known shop doesn't supply the Tin extensions.

I'll be curious to see if yours has the same issue. Hope it doesn't for your sake.

From what I'm seeing this barrel will be going back also. They should have listened the first time when I told them these extensions were soft.

My second one was the same as the first. After 15 rounds I could see the same deformation in the feed ramps. Third one the assembly job from rainer was terrible and I was offered to send back the barrel and get my money back, and I did. Their asembly snafu was ironic since they were the ones who wanted to assemble it, to make sure I wasn't fucking it up.


I was mostly treated like the problem was my fault. Any idea the the barrel extention could be the problem was dismissed. I was condescended to about assembly, springs, and buffer weights by someone I proabaly wouldn't let put air in bike tires.



Now I am shooting A CMMG and xcaliber 6 arc barrel and no extention problems over 250 and 100 rounds respectively.

 

[padom]

That's not good to hear. I'm.not sure I even want this barrel now.

 

[supercorndogs]

That's not good to hear. I'm.not sure I even want this barrel now.

Make sure to keep an eye on it. The headspace on mine grew about .014 also over 400-500 rounds. The first two pictures are the first barrel. The second are the second barrel after 15 rounds.

 

[padom]

Make sure to keep an eye on it. The headspace on mine grew about .014 also over 400-500 rounds. The first two pictures are the first barrel. The second are the second barrel after 15 rounds.

View attachment 8453431View attachment 8453430View attachment 8453429View attachment 8453428

I just canceled my Rainier order and ordered a RTR 22"... I have zero interest dealing with issues out the gate.

 

[supercorndogs]

Ya. That's where I landed and why I have an xcaliber barrel that just showed up a week or two ago.

 

[padom]

Ya. That's where I landed and why I have an xcaliber barrel that just showed up a week or two ago.

How does the RTR barrel shoot? Especially sith the 80-95gr bullets?

 

[supercorndogs]

How does the RTR barrel shoot? Especially sith the 80-95gr bullets?

Sorry I meant I didn't want to deal with more problems. Not that I had an RTR barrel. If I had thought of the RTR option. I don't know if I would have bought one from xcaliber. That's PVA rockcreek button blank correct? So far the xcaliber barrel seems pretty promising.

I see RTR is Craddock. Intersted to hear about them.

 

[Kocher]

I had issues with mine from Craddock so far they said that they’ve not had one ever not shoot. They’ve been excellent with communicating. I just can’t figure it out.

I’ve got everything buttoned up tight. I may try a different scope. I really don’t want to because this one seems to be doing fine.
….

I’m gonna give it another go I’ve been shooting 87 grain Vmax and 108 ELD’s

If you want speed, the double base powders are the only way to go the stick extruded just don’t have the speed you’re gonna be down 150-200 FPS

87 gr vmax 30.3= 2977 fps average
22”
I will be trying virgin brass with no a anealing or anything I’m just gonna set the bullets in and see what happens..

I’ll have to see

 

[Mmdutcher]

I am new to the 6mm ARC cartridge. Been trying different things out myself and am on a journey to find that right setup for my reloading. So far I have not had that great of success with my reloads. I hoping that it was my barrel choice within my build. I have since corrected my ways and am looking forward to an 18” Proof carbon barrel.

Once I have that built up, then I will resume with my 103, 105, and 108 gr loads again. I am optimistic to get to some better performance once I have that new barrel in place.

Looking forward to continue to take in all of this new content from you all as well.

 

[Dogtown]

Ok cool.

 

[rlsmith1]

Got my 14.7” RTR out today and it seems to really like the factory 80 ELD VT’s, very small clover leaf at 50y tonight (my 18” Proof SS does not like them at all).

Slower velocity than I’d like (2695 fps) but an SD of 6 across the 3 shots picked up by my chrono is good to see. Hope I gain 50-100 fps the next couple hundred rounds like my Proof did

 

[db2000]

Got my 14.7” RTR out today and it seems to really like the factory 80 ELD VT’s, very small clover leaf at 50y tonight (my 18” Proof SS does not like them at all).

Slower velocity than I’d like (2695 fps) but an SD of 6 across the 3 shots picked up by my chrono is good to see. Hope I gain 50-100 fps the next couple hundred rounds like my Proof did

Look at 5 shot minimum, and 10 shot preferably, groups at 100 yd. That’s a more realistic evaluation of what the barrel and you are capable of. Take your time and concentrate of good form.

 

[rlsmith1]

Look at 5 shot minimum, and 10 shot preferably, groups at 100 yd. That’s a more realistic evaluation of what the barrel and you are capable of. Take your time and concentrate of good form.

Of course; I was more looking at if this barrel would like the 80’s because my Proof would shoot them 2 MOA at best but put the ELD M / ELD X sub MOA for 5 and 1.1 to 1.2 for 10 shots. Since I’m still in the first couple hundred rounds on this barrel I was just trying to get an idea of speed and if these factory loads shot well

 

[supercorndogs]

What's better ten 3 shot groups, six 5 shot groups, or two 3 shot groups then go shoot it as you plan to shoot it, and see if it meets your needs?

 

[rlsmith1]

6 five shot groups is certainly ideal but I had a box of 20 rds and wanted to coyote hunt later

 

[supercorndogs]

I think option 3 is ideal for most shooters.

 

[db2000]

I think option 3 is ideal for most shooters.

All 2-3 shot groups with clean cold barrel for hunting rifles for sure. Definitely want to see consistency with that first shot obviously.

 

[bbyars]

interested to hear how those RTR barrels shot, currently have one in the cart but hesitant.

 

[padom]

interested to hear how those RTR barrels shot, currently have one in the cart but hesitant.

Shot great lots of results in 6ARC thread already posted