Released today...

Figures after I get a 6.5 Grendel they standardized a 6mm version. It isn’t just a necked down Grendel but close enough.

Looks fun and now I may end up needing another upper.

Wish they’d done it with the TAC 6....no bolt vs limited pressure worries (the bolts may not be an issue anymore, but I’m sure the pressure is still kept lower) and same or better velocity, IIRC. Like to see how it does in 16-18....could be useful. The case head vs bolt vs pressure in an AR has always seemed like the Grendel case was hamstringing itself to me. If all else was the same, with a smaller case head/rim size, it could get out of its own way better....but it still does better than most in high BC needs/apps.

It looks pretty promising. Hornady claims they get 2,700 fps with the 108gr ELD match bullets, having a bc of .536. Ar performance had 20" barrels on sale for $200.00 too, but they are currently sold out. The nice thing about it is availability of components and die sets, plus factory ammo. Maybe it will gain enough popularity to make it worth while, like the 6.5 cm.

I dig it!

Me too. You guys probably got the emails from hornady and midsouth and other places, but the one from midsouth has a bunch of links about this new cartridge. They also have die sets. A big plus for guys looking for a good 6mm ar15. I wish my 6WOA had more support, like finding brass, die sets and load data. But WOA kinda has you bent over a barrel. Things like that will cause a cartridge to become obsolete. Hornady is doing it right with this cartridge.

Looks good.

I like the sound of it. About what I'm getting with my 6 TAC but factory dies, brass, load data. A .224 versions may be better on paper but with regulations in many states requiring a .24 for big game it checks that box.

This one has me thinking I need to get into the AR game. Now the only question is buy a complete rifle or build one.

Many ways to skin that cat. You can buy a complete upper, then build the lower, or buy a complete lower, or buy the parts and assemble it yourself, as well as buy a complete rifle over the counter. Here's a link Midsouth sent me on this new cartridge:


Midsouth links to 6mm ARC

You know I didn't need one until you told me about it!

Pretty sure I owed you one!

Thank you. Trying to decide the best way to go. I’d like to end up with something that is accurate enough to shoot out 400-500 yards. Looks like there are lots of good options out there.

JBM says that the ELD 108 has 1.3 MOA less drift at 600yds @ 2750fps MV than a Sierra 80 .224 at the same specs.
Looks useful.

I feel the same. I don’t own an AR, but with the current environment, I have been thinking it was finally time to get one. I have put it off partly because there seems to be some debate regarding the adequacy of the 5.56 and ongoing discussion of a new service round. 6mm makes sense in a lot of ways.

I was real close to just going the 5.56 route, but now I will hold off a bit to see if the 6mm ARC takes off. It looks good to me.

Slope,

Get one now in 5.56 and buy an upper or 6 ARC barrel and bolt later. It'll work on the same lower.

Now isn't the time to delay buying an AR, IMHO.

You and I are not tied to FMJ's like the Military.so I don't feel that it's an issue.



Adoption of the Army's new round, rifle and SAW, is I believe like two years out... if it even happens this time. The Army has gone down this road in the past and done nothing. Though I feel this time may be different?

But, if the 6mm ARC is what moves you, go for it

Jerry

8" less wind drift at 600 could mean a big difference in any discipline. Hunting or target shooting. I'd take it.

I played with the Grendel in several bolt rifles and one AR. I came to the conclusion that it is better to use the designed for AR cartridges in AR's and use cartridges designed for bolt guns in bolt guns. In the same short action I would have to use for a 6MM ARC I could have it chambered for other more capable 6MM's.

tag

I dont see a need for it in a bolt gun. Too many good options readily available for it. In the AR platform, however, is where it will shine. Something a lot of the other guys in the other forums dont get is how limited of a selection we have with the AR15. We are limited to a certain oal (2.255" generally) on our ammo, so it feeds reliability. A lot of guys dont want to buy an ar 10, either, because they are bigger and heavier than a similarly built ar15. We have a better selection of ammo with the ar10, but the drawbacks literally outweigh the benefits at times.

Of course I just built a 243 LBC last year...lol

Dan

Well I picked up an Aero stripped lower and an Aero lower kit to with it this afternoon. I went with a Luth-AR MBA-1 rifle stock and I ordered dies and brass from Midsouth. I think I’m going to watch for a complete upper to finish it off. Looking forward to playing with this one.

Hornady has on their website a list of suppliers who have supposedly gotten on board with this cartridge release, providing the various items necessary to build complete rifles. Some well known names, some I've never heard of. But then, I am not "ear to the ground" when it comes to ARs. I will say that I have been thinking of building a dedicated rifle for hunting/target purposes, and NOT chambered in .223/5.56. While wading through the various options and the pros/cons of each, this cartridge snuck up on me. I like what I hear, and am tempted to buy in to the initial hype. I think Hornady tends to do the groundwork on "their" cartridges pretty well. Maybe I am mistaken, but I think they've hit more home runs than fouls as of late.....

Kaiser Norton

I built two and have no regrets. The new cartridge may be available as a factory load, but I'd still shoot only handloads no matter what. One benefit is that there will at least be some data available that is close to 6mm AR...but the new factory round will have less case capacity and therefore more conservative max loads. At least we'll have another clue to consider.

I would say you are right as rain on that one. I really liked the idea of a 6mm ar a while back, so I opted to buy a 6WOA. There is damn near no support with that one. You only have one choice of dies, and you have to beg WOA for load data.. I'll buy a 6mm ARC and be a whole hell of a lot happier..

Umm, the Grendel (and the current 6 ARC, and all it's 6mm Grendel wildcat predecessors) are cartridges designed for ARs. That's why they're the length they are, instead of something longer (for hunting/varmint guns) or shorter (for benchrest). What makes you think they were designed for bolt actions?

This, no regrets from me either, and I ordered another blank yesterday to build a third (a 12.5" this time, already have a 19" hunting setup and a 24" long range setup).

For a guy who handloads, the standard Grendel necked down to 6mm is easier than bumping the shoulder back too (and dealing with the resulting donut in the neck), and good Lapua brass is available for the Grendel, not so much for the ARC. For the handloader I think something like the 243 LBC is the better option, while still being able to take advantage of all the improvements that will come in magazines and more bullet options.

I basically asked rickt300 the same thing in an earlier post. I think I tried to explain why we get the short end of the stick when choosing a good 6mm AR15 cartridge. Also, brought up guys pizzing and moaning about the 6mm ARC in the hunting rifle forums, saying it brings nothing new to the table. "Other cartridges are better", so they say. One guy even commented about his 6x45 being an equivalent. I also called bs on that statement. I also stated why this cartridge will succeed big time and its about time we get a good 6mm cartridge we can use in our AR15's, without having to go to a bigger heavier AR10, or a wildcat with no support. Yeah, this cartridge doesn't have the poop of the 243 winchester, but this cartridge was designed for an AR15, not the AR10. Also for your statement above, there will be more "better" brass available for the 6mmARC. Trust me on that one..

I don't keep up with these 6mm AR cartridges much. Which ones support mag-length loading of 105+gr bullets?

IMO Hornady just wants to sell more ammo. Did the Army really pick up on this round like I heard? That could make a difference. I'd rather have a Grendel myself. More bullets are available in 6.5 nowadays with better BC's. Brass is readily available. Just another sales pitch from Hornady. They can't let Nosler out-new cartridge them.

I never said they were, all I meant was that they are designed for and at their best in the AR15 platform. I am waiting patiently for a good upper to come my way in 6MM ARC. Probably play with it for a while and go on to the next cool cartridge. Still have my Grendel upper and like it. However 2700 fps and a good BC bullet might just replace it.

Well, they ARE a business. That said, I look at what they've accomplished with the 6.5 Creedmoor and the success that has become. When I look at the wealth of loads available for that cartridge at the local Funstore, the only thing that is comparable is the .223/5.56. The way I see it, they brought the Creedmoor out as a target cartridge, put out a wealth of options for it, and fully supported it (Listening Remington? Do you hear the .260 crying in shame). Then they got Name shooters/builders on board and built a following for it. Viola...success. Looks to me they are trying to follow the same blueprint with this cartridge. Maybe it'll fly, maybe it won't - time will tell.

Kaiser Norton

That was exactly my take on your post above.... There infinite options with bolt rifles.

does it use 5.56 mags, or need special magazines?

The 6mm ARC uses special Grendel magazines. The case is too fat for 223 magazines. There are some good options.

Brand recommendations, please!

Kaiser Norton

I’ve been using ”C Products Defense” 10 round magazines with my Grendel. I’ve had no feeding or function issues with them and I shoot suppressed which means they get extra dirty.

I'd try ASC mags as well. I use them for my 6WOA. They work very well... I also use another brand, but can't think of it at the moment... These are steel mags and I've never had any problems with them..

Considering gas systems, any thoughts what would work for this? Or other considerations taking a 5.56 upper changing barrel and bolt. Are maybe just changing from a 6.5 Grendel.


Faxon at Brownells will have Mid length for 16 and 18".

If going 18"+, I'd go with a rifle length gas system. You can also use an adjustable gas block like a lot of guys here run, or without an adjustable gas block and just run an H2 buffer, or something in the 4-4.7 oz. weight range. You could also use a captured spring system like JP or the Armaspec stealth.

Thanks.

I've managed to talk myself out of NEEDING a 6mmARC at least a dozen times already.... Curse you 'Fire!

I have an AR that is begging for a new barrel. In its current form it’s an honest 1.5 moa barrel. So thinking I will jump on the preorder from Brownells and get the 20 inch barrel. Oh and the Grendel bolt. Right now I’m waiting on parts for a 224 Valkyrie build..

John, keep us posted. I was just eyeballing the 20" barrel at brownells as well. I'll bet its going to be a shooter.

John,

A 1.5" AR is "begging for a new barrel?"

I remember when that was a rock star group for an average AR.

J's been shooting competitively now, for a little while, and must have caught the accuracy bug. Check out the black rifle challenge here, there are some of us here that believe ar's can be extremely accurate. A lot of us aren't talking 3 shot groups here either. J is one of those guys. Like me, when you shoot comp, you fire more than 3 shots on target, and you want them to be in the X-ring. If not, you might as well be golfing or fishing.. Here's how my iron sight AR did in the black rifle challenge here, and its better than 1.5":



It also scores an average of 100-8x. rost has said a few times that a good ar and good shooter can hold moa for 10 shots with irons.. He can correct me if I'm wrong, or I can find that exact quote from the challenge. When I heard that, I questioned it, but with the rifle I'm shooting, it's starting to prove his theory.. I'm like John, I believe with an optic, you should be well within 1 moa for 10 shots with a good AR. Not every AR, but with a GOOD ar... Here's how my Northtech Defense shoots pretty much all the time (well, it hovers around .8 MOA consistently):



As a side note: All of my AR15's have shot sub moa scores in the black rifle challenge here, except for my iron sight Noveske... Even with a scope, it just hovers around 1.1 moa...

lol you are right 3-4-6-8 yrs ago i wouldn’t of cared.. but after shooting matches last yr and x count along with 10’s. You need a AR that is an honest MOA rifle, my current setup with a green mtn barrel fits that bill great barrel. I used the PSA built AR with there barrel half the season last year and realized.

Realized PSA just wasn't cutting it, didn't you...

We all aren’t big money hustlas like you.. PSA is a good starting point it did what I needed it to do.. I might need to clean I have no
Idea the last time I cleaned it. But it’s very picky and it won’t shoot the bullets I need it to shoot 77 Sierra’s.. i thought about putting a 20 inch green mtn barrel.. But we have a 1000yd shoot coming up... none that 100 yd [bleep] you been doing lol 😜I’m just busting your nuts. But we have a 1000 yds nra high power shoot 60rds. If the stars align I will use this 224 Valkyrie. With 80 eld-m we will see..

Good luck buddy. Damn, you need an ar10 6.5cm for that 1000 yard match... are you going to be using your 1-4 scope? Id be fu cked, if i had to use a 4x at 1000!!!!

Hell no lol i will use a 10x.

Irons all the way!

Looks like 2700-2800 velocities are via 24" barrel.

18", probably in the 2500 fps range?


https://gununiversity.com/6mm-arc-review/

The claim is 2630 FPS for a 108 gr. from 18":


https://www.tactical-life.com/news/barrett-rec7-rifles-hornady-6mm-arc-dod-contract/

I'm thinking a 20" barrel might be about right...

Exactamundo

I finally jumped and ordered a CMMG complete upper with a 20” barrel. Looking forward to getting everything put together.

Should be pretty sweet. Buying a complete upper is going to save you a little time. I think if i were going to build one from scratch, id just go with Aero precision (upper and lower M4e1) and a Faxon 20" barrel from brownells ($216.00). Im thinking i could keep the cost below $800.00 for the complete rifle.

I’d like a 6 ARC upper myself.

Pretty much all of the Grendel-based 6mm wildcats (including the 6mm ARC) do that. Almost none of the 6.8 SPC-based or 5.56-based wildcats do. That's the entire reason the Grendel case is popular for these cartridges - to fit long heavy bullets at mag length.

In my 243 LBC barrels (one of the most successful Grendel-based 6mm wildcats) my accuracy loads for the 105gr BTHP and for the 95gr VLD which actually has a longer nose are both less than 2.260" OAL, even though 2.300" or slightly longer is possible with ASC mags. This is one of the few AR cartridges I've used where magazine length is not a restriction on potential accuracy due to jump to the lands.