White Oak Armament's thoughts on 6mm ARC

[LVLAaron]

I called them to see if they could spin up a 6mm ARC "service rifle" barrel. They pointed me to this entry:


https://www.whiteoakarmament.com/blog/hornady-s-new-6mm-arc.html

 

[Walt Krafft]

That echos my experience shooting a 22PPC. Have quite the pile of broken lug bolts.

 

[Cemetery21]

John at WOA has given me good advice on a couple of other matters over the years.

 

[jelenko]

My perception is that John at WOA is 'conservative' - a good thing when it comes to safety.

 

[David Milisock]

Clearly some intelligent discussion, which leads toward factory ammo or conservative hand loads. Still the ballistic results from 52,000 PSI make for a viable 6MM in an AR 15 platform. I'm definitely going to continue my research toward obtaining one.

 

[LVLAaron]

Clearly some intelligent discussion, which leads toward factory ammo or conservative hand loads. Still the ballistic results from 52,000 PSI make for a viable 6MM in an AR 15 platform. I'm definitely going to continue my research toward obtaining one.

Same. I really want one... but I'll let WOA do the battle testing before I blow 1000+ on a match barrel/upper

 

[Rustytigwire]

Can I get good velocity from 87 vmax or 70 tnt for splody little harmless critters?
Is there enough OOMPH in this cartridge to do that??
Do I need 107 or 105 at 3000fps???

 

[David Milisock]

Can I get good velocity from 87 vmax or 70 tnt for splody little harmless critters?
Is there enough OOMPH in this cartridge to do that??
Do I need 107 or 105 at 3000fps???

From what I read it's similar to 243 Winchester ballistics out of an AR 15 platform with a 24" barrel. That's good for varminting and medium game. It's not 6MM Remington performance but it's not 65,000 PSI either.

 

[Spook]

....and then theres the issue of hornady brass

 

[Evan]

....and then theres the issue of hornady brass

I see that as a plus in a gas gun. I'd sweat losing a piece in the weeds a whole lot less and my past experience with hornady brass is that it is entirely capable of consistent half MOA, unsorted but neck turned, when all the other components are up to snuff. I don't think it will ever be the limitation in an AR-15 platform. In a quality bolt gun, maybe start with 220 or 6.5 Grendel Lapua instead and form it.

 

[dfry]

I used to shoot the 6 WOA as a match rifle without ever a problem, then had to just try the fat rat. Never pushed it hard and still broke a lug. Decided it wasn’t for me just to much bolt thrust and went with a 240 Tomahawk (basically an AI 6 WOA) shoots the same as a Hagar, and have never had a problem and it performs very well. The .440 head size I also agree is probably just to much in an AR15 unless you keep the pressure down, and most HP shooters won’t!
Dave

PS: I know there can be problems with Hornady brass And it is not Lapua, but I used a bunch of it forming from 6.8 and some of the groups were just scary small. I had more problems with SSA brass. The 87 Hornady BTHP shoots great on short line.

 

[Walt Krafft]

From what I read it's similar to 243 Winchester ballistics out of an AR 15 platform with a 24" barrel. That's good for varminting and medium game. It's not 6MM Remington performance but it's not 65,000 PSI either.

Physics will not let you get the same performance from 30 grains of powder you get from 40 grains. It ain't no 243.

 

[David Milisock]

....and then theres the issue of hornady brass

I seek enlightenment. I have only used Hornady brass for a custom made 450 Marlin using 500 grain projectiles from a Mauser 98. I have no problems with the brass. For field accuracy I have not seen much difference in brass excepting some military brass with the primer holes all over the place. I would sing a different tune if bench resting. I also only load and shoot a single lot of brass at one time, if a few go bad I trash the entire active group of brass.

To define field accuracy I consider 1 1/8" to 1 1/4" at 300 yards reasonable accuracy.

With that said for my Howa 1500 in 223 Remington I do use a Malaysian military brass for my 40 grain Hornady VMAX load as it allows 2 grains more powder. Yes I know it needs swaged but I got 1,000 cases once fired for $5 and the load shoots 1 1/8" at 300 yards and clocks at 3,900FPS.

So what's the good, bad and ugly of Hornady brass?

 

[David Milisock]

Physics will not let you get the same performance from 30 grains of powder you get from 40 grains. It ain't no 243.

Agreed which is why as a bolt gun it holds little interest for me. However with off the shelf ammo for both the 6mm arc andv243 it's close enough a pig won't notice.

 

[Spook]

I seek enlightenment.
So what's the good, bad and ugly of Hornady brass?

the good: its inexpensive
the bad: its soft
the ugly: Ive had to pry one brand of brass off of bolt faces more that any other, and that brand is hornady. to say that the primer pockets didnt hold up for me understates it somewhat.

 

[David Milisock]

the good: its inexpensive
the bad: its soft
the ugly: Ive had to pry one brand of brass off of bolt faces more that any other, and that brand is hornady. to say that the primer pockets didnt hold up for me understates it somewhat.

Thanks, I've been hand loading over 50 years and have never had the pleasure of prying brass off a bolt face. I stick to the if it won't open with a pinky finger back off method of load testing. However I am patient and may take 2 years to work loads.

 

[Evan]

Physics will not let you get the same performance from 30 grains of powder you get from 40 grains. It ain't no 243.

Well, I know how the ARC can equal a 243: load a 243 at 40ksi and load the ARC to 52ksi. Voila! They're equals!

 

[Hohn]

I called them to see if they could spin up a 6mm ARC "service rifle" barrel. They pointed me to this entry:


https://www.whiteoakarmament.com/blog/hornady-s-new-6mm-arc.html

No surprise, you over stress parts and they break. If the ARC won’t give you what you want at 52ksi, try something else. Or push it and risk breaking.

 

[David Milisock]

Well, I know how the ARC can equal a 243: load a 243 at 40ksi and load the ARC to 52ksi. Voila! They're equals!

With 108 grain projectiles Handloader Journal shows the 243 at 2850, Hornady lists the 6mm ARC at 2750 with a 108 grain projectile close enough not to argue about.

Now the pressure for the Hornady can be assumed to be nominally maximum. The load manual shows their load as max but the pressure is assumed to be near max but I'm betting it's conservative.

In any case the average hunter who wants a durable, low maintenance, self loading huntingbrifle and sees these numbers will see the 6MM ARC as close to the 243.

 

[tomswede]

Soft brass in an AR is not a good idea! There is a reason ( very hard learned) that the mil spec 556 brass has the hardness requirements it has.
Seems to me that this is trying to do something the platform is not designed for not leaving any margin.