6mm ARC

[high country]

I have had an itch to set up a Howa Mini Action in a 6mm cartridge for some time, and am considering whether that time is now. 6mm ARC is the obvious choice. There are barreled actions available to backorder (no idea what the timeframe on that currently is), or I could order a preferred barrel and convert the one I have in 7.62x39.

But, I have looked around for brass in 6mm ARC, and it seems like slim pickings. This may belong in the reloading forum, so feel free to move it if need be. I would rather not have to make brass from something else but I suppose I could if I needed to. Although, I would figure on forming from 6.5G, which also seems a little tough to come by at the moment. That would be my first foray into making brass, and forming from 7.62x39 to 6arc seems challenging.

So, is this a bad time to be getting into 6arc (or 6.5G for that matter)? Does anyone make it other than Hornady? The Hornady brass looks like it is about $1 EA if you can get it, which seems like it is getting more in the Lapua price range, but in my very little bit of experience Lapua is demonstrably better brass when working with it on the bench.

I would prefer not to sink a bunch of coin into a rifle that I felt I was always fighting with due to unavailable quality brass. I don't need a ton of it, a couple hundred would get me started and last a good while, but I don't see any. I am also considering doing the build in 6.5G, but that seems to have some of the same challenges with brass availability although not quite as hard to find.

 

[Gtscotty]

I really like my 6mm ARCs, to be fair though, I have not seen component cases available the whole time I've owned it. One of my local gun stores has kept a pretty good supply of 108gr ELD and 105gr Black factory loads for decent prices, so I've just shot up factory loads and reused the brass.

I've heard that Starline is going to start making 6mm ARC cases this spring, hopefully that's true.

In the mean time you could order several boxes of 108gr ELD and get started shooting some pretty good ammo and wind up with your cases:

https://www.scheels.com/p/hornady-e...3422&utm_medium=affiliate&utm_source=AmmoSeek

 

[Varminterror]

Cases are coming around. It’s been a very popular cartridge which was released during the largest consumer demand surge in the history of the world, so it’s pretty easy to appreciate that finding brass right now might require a bit of patience and a bit of diligence.

Factory ammo in a bolt action is fun, but doesn’t get quite the performance which can be attained by a reloader. A reloader can pick up a 150-200fps over the lower pressure standard used in factory ammo, loaded as such in deference to the lesser structural tolerance of the AR bolt. We can do a lot with a 108 at 2700, but we can do even more at 2900.

 

[high country]

@Varminterror, you make a good point about the timing on the release. You are getting 2900fps with a 108 grain bullet? That's fast! I was thinking I would try 105 BTHP over CFE223 for starters. My plan was for a 20" barrel, so I will be giving up some velocity there. I was guesstimating I would be in the 2700-2750 range. I would be quite happy with that if I landed on a consistent load somewhere in there.

@Gtscotty also makes a good point, it has been so long since I bought factory ammo. In large part due to the shortages Varminterror referenced, I just stopped even bothering to look for it.

At $1.50 a round loaded, and a brass case worth $1 new, it makes good sense to buy loaded ammo for the brass if you are going to be working with Hornady brass anyway.

On a related subject, in deciding whether to seek out a Howa barreled mini action, or getting a 6 ARC Preferred Barrel to put on the 7.62x39 action I have now, any sage words of advice?

A new barrel would be a couple hundred more since I wouldn't end up with two rifles. I'm thinking I would be ahead in barrel quality with the preferred, but not sure. I understand (and in my limited experience) the Howa barrels tend to be good. It would be used primarily as an informal target rifle, and shooting steel at longer ranges when I have a chance. Mostly, it looks like a neat round to load, and then unload using a handy accurate little rifle. What's not to like about that.

 

[Varminterror]

If you have use for the 7.62x39mm rifle as it is, then I’d leave that alone. But I generally plan for $700 for a new barrel and smith work, whereas I’d pay more than that, typically, for another scope, let alone another complete rifle, so rebarreling is far, far cheaper in my calculus - so if I had an x39 rifle I didn’t need, I’d be very tempted to rebarrel to 6 ARC.

You’re definitely not going to get 2900fps from a 20”, but the advantage of bolt action pressure standard at 62kpsi will remain to outrun factory ammo considerably. The ARC is a blast to shoot either way - it’s within the realm of what I typically state as “ideal” for deer hunting; enough enough, but not too much on either end.

 

[12Bravo20]

Hornady is the only company making commercial ammo right now. Black Hills has announced at SHOT Shot that they will start producing their own 6mm ARC ammo loaded with 103Gr ELD-X bullets, but no release date has been announced. I will say that ammo availability has improved even over the few months since I built my 6 ARC AR.

I say go for it if you want to build a 6 ARC bolt action.

As far as brass goes, you will either have to save your empty Hornady cases or you can reform 6.5 Grendel brass to 6mm ARC.

I recently built a 6 ARC AR and enjoy shooting it. I went with an 18" barrel so I do loose some velocity compared to a longer barrel, but I wanted my AR to be handy for me. For a bolt action, I would definitely go with a longer barrel at least 22" long.

It was a toss up between 6 ARC and 6.5 Grendel when I built my last rifle. I decided on 6 ARC just to have something in the 6mm family even though ammo is harder to find.

 

[troy fairweather]

Peterson said they will have 6arc and 6.5 prc ammo this year so probably brass to, I can get 6arc locally for $27 plus 5% off so covers tax and if buying similar components it's cheaper for the ammo. Just got my 6 arc together and things looking promising, only had a chance to shoot 5 rounds yesterday as it was getting dark out and at 25 yards all 5 were touching, not bad since I couldn't see my cross hair on the black dot on the target.

 

[12Bravo20]

I will definitely try other brands of ammo once it is available. So far I have only shot Hornady's 103Gr and 108Gr ammo out of my AR. The rifle prefers the Hornady 108Gr best, though 103Gr still isn't bad at 100 yards.

The 108Gr shoots 3/4" at 100 yards while the 103Gr shoots 1" at 100 yards out of my 18" Odin Works barrel.

 

[high country]

I would probably end up parting with the x39 if I am being honest with myself. I feel like the 6 ARC would fill pretty much the same role with the added benefit of not falling off past 200 yards like the x39 does. The preferred barrels look to be about $440 with the nut to convert to a howage setup. There would be tools (clamp, wench, and gauges) but I tend to allocate those to "shop" costs as opposed the cost of the gun in case someone (my wife) inquires about how much I sunk into a project...

Any thoughts on the quality and likelihood for good accuracy as between a Howa factory heavy barrel and a Preferred aftermarket barrel?

It was a toss up between 6 ARC and 6.5 Grendel when I built my last rifle. I decided on 6 ARC just to have something in the 6mm family even though ammo is harder to find.

I am having that same debate as well, barrel actions in 6.5 Grendel appear to be more readily available. It is probably six of one, half dozen of another for my purposes, but for the same reason as you I am tempted to go with 6 ARC.

 

[lightman]

Someone just gave me a loaded cartridge for my collection! Its a cute little thing!

 

[12Bravo20]

I am having that same debate as well, barrel actions in 6.5 Grendel appear to be more readily available. It is probably six of one, half dozen of another for my purposes, but for the same reason as you I am tempted to go with 6 ARC.

Let me be a bad enabler then. Go with the 6 ARC! Consider your arm twisted

 

[rdnktrkr]

I like the 6 ARC and I have a couple of Grendels, the Grendels shoot great and my friends ARC shoots great also, my 20 and 24" barrels and my friends 22" seem to shoot better than his 18" Grendel. I've been looking at building a 6mm AR or purchasing another bolt action in a 6mm PPC, Dasher or Creedmoor. My friends SIL said a Howa is easy to replace the barrel and he would help if I went that way.

 

[high country]

Let me be a bad enabler then. Go with the 6 ARC! Consider your arm twisted

I feel like that is what I want, and if I went Grendel I would always wish I had just done the 6mm the first time. A ~100 grain high BC bullet going that speed covers a lot of bases from my perspective.

The 6 ARC barreled actions are on backorder on Brownell's, but it will let you put in an order. I am going to give that a try first, then if that fails I will re-barrel the one I have.

 

[12Bravo20]

I'm glad that I could help corrupt you

 

[high country]

As I am looking at options for this, it looks like savage is using 1:7.5 twist in its rifles, and that seems to be the preferred twist for the heavier long bullets. But, the Howa factory barrel has a 1:8 twist.

Any experience with using the 108 ELD-M in that slightly slower twist? The Berger stability calculator suggests stability could be marginal. Anything shorter/lower B.C. looks to be OK, but it seems like there might be a ceiling on the bullet weight with that twist.

 

[kmw1954]

A friend I work and shoot with just worked up a Savage 110 that came as an ARC. He has since replaced the barrel with a Shilen Match and added a chassis stock. With hand loads he is shooting 1/2MOA at 300yds. I had thought of doing the same thing instead of going the 6BR route.

 

[gunmechanic]

My next bolt gun will be 6arc .I just finished my 6arc ar15 build i went with an odinworks 21" 6arc barrel with +2 gas system and there adj gas block .It would fire first round then 2nd round would not strip and load into battery or hold back on last round.I am using rifle length tube, buffer & spring .To get it to run i had to open gas port from .85 to .103 now adj gas block is at 8 clicks open and it runs like a scalded dog.I wanted a howa mini action in 6 arc could not find one i got one in 6.5 grendel instead ( wanted a bolt gun in grendel also) but want a 6arc bolt so i can load it up to bolt action pressures and see how the round will perform.I wish cz still made the 527 it would be a great 6arc platform sad they discontinued that model it is one of my favorites !

 

[12Bravo20]

My next bolt gun will be 6arc .I just finished my 6arc ar15 build i went with an odinworks 21" 6arc barrel with +2 gas system and there adj gas block .It would fire first round then 2nd round would not strip and load into battery or hold back on last round.I am using rifle length tube, buffer & spring .To get it to run i had to open gas port from .85 to .103 now adj gas block is at 8 clicks open and it runs like a scalded dog.I wanted a howa mini action in 6 arc could not find one i got one in 6.5 grendel instead ( wanted a bolt gun in grendel also) but want a 6arc bolt so i can load it up to bolt action pressures and see how the round will perform.I wish cz still made the 527 it would be a great 6arc platform sad they discontinued that model it is one of my favorites !

I am surprised that you had those issues. My 18" Odin Works barrel has the +2 gas system and I didn't have to adjust the gas block from where it was set at the factory. I am using a standard weight carbine buffer with a MagPul PRS Lite stock. But the buffer system should not make a difference.

I would like to have bolt action in 6 ARC but most that I have found are only available in right hand rifles.

 

[high country]

I wish cz still made the 527 it would be a great 6arc platform sad they discontinued that model it is one of my favorites !

You can say that again. I have one in .223, but if it were in 7.62x39, I would very tempted to send it to pac-nor to be barreled in 6arc.

What twist rate are you guys running in your 6arc setups? It seems like the prevailing wisdom is to use 1:7.5" to stabilize the 108gr ELD bullets. The Howa specifies that their barrels are 1:8", and I have some concerns that that might not stabilize those long bullets. The Berger stability calculator suggests it might be a close call.

 

[Gtscotty]

Someone just gave me a loaded cartridge for my collection! Its a cute little thing!

It's a funny little case with big long bullets sticking out.
Here is an ARC loaded to mag length with a 112gr Matchburner next to a 6mm GT loaded with 108gr ELD. The 112gr is very nearly as long as the case.


ARC with a 105gr MB next to a Dasher with 109gr. The Dasher is bigger for sure, but the difference isn't huge.

 

[troy fairweather]

I'm sure it's possible in a bolt gun running 62k or more but it would be cool to hit 3000 fps with a 87 grian, not sure I can in my 22" Shaw barrel in my ar 15 keeping pressure were it should be. The heavies are nice in the arc but think I'd like playing around with the 75-95 grain bullets, if like to find a bullet that would be good for deer and some varmint or paper. I wonder what the lightest 6mm with .400 bc it should have some speed but still do ok out farther. I read the coyote guys like the 70 btip, seems to really put them down and still not have to much drop out to 500.

 

[USBP379]

I talked to Starline briefly at SHOT. They do not have plans for 6 ARC at this time.

Really only three options at this point:

Factory ammo and then reload.

Grendel brass sized and trimmed. Works well.

Forming brass from something else. I've made probably 750 pieces of ARC from 7.62x39. Works well but is time consuming. Also some brass is harder to form than others. Norma comes to mind. Lapua is another that doesn't form as easily as some others. I've also made ARC from .220 Russian but the cost of these probably doesn't warrant using them over 7.62x39.

 

[12Bravo20]

Black Hills is suppose to start producing their own 103Gr 6 ARC ammo sometime this year.

Right now I am making sure to save all of my Hornady brass.

 

[USBP379]

Black Hills is suppose to start producing their own 103Gr 6 ARC ammo sometime this year.

Yep. Talked to one of the BH reps at SHOT. He had no info other than it had been announced....

 

[12Bravo20]

I'm starting to think about switching my Savage Model 12 from 308 to 6 ARC since 308 is beginning to be too much for me with my disabilities and shoulder injuries.