You're making me feel a LOT better about my choice. A buddy of mine and I have been shooting 6 mm WOA for about 3 years now. It has a longer neck and is designed more for the longer, heavier, higher BC bullets. I have a 16" BHW 6 x 6.8 barrel in the safe that I am getting ready to spin on. I chose the 6 x 6.8 in a shortish configuration because I want to run a suppressor with 58 gr V-Maxs in a nimble platform and as a truck gun. Should be FAST and great for coyote/varmint hunting.
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New 6mm Advanced Rifle Cartridge
- Thread starter Gtscotty
- Start date
Hornady seems to be marketing 6mm ARC as a novel 'beginner' cartridge for PRS bolt guns, too. Not quite the same performance as Dasher, but much better barrel life and commercial match ammo. I'm going to be participating in my first Tac division PRS match at the end of June with my .308, but I'm planning on building a 6mm after about a year or so. 6mm ARC looks like a pretty tempting way to get into the stumpy-cased 6mm game. My biggest concern is that the commercial loadings really won't be going fast enough to be competitive on targets beyond 1000 yards. I'll be doing my own reloads anyway, though.
I'll be watching very closely to see what you all have to say about it!
I'll be watching very closely to see what you all have to say about it!
I am actively trying to stop reloading, so all the 6mm wildcats don't do anything for me. This cartridge looks like a good option. I am guessing Hornady will likely end up keeping ammo prices in the same general range as their 6.5Grendel ammo, which is pretty reasonable. Some earlier posts here show ~2600fps velocities out of an 18" barrel with a 108gr buller. If that proves out to hold with factory ammo, I will definitely buy a barrel from Proof and build a DMR-type upper. I still have a couple of thousand round of Grendel ammo here, but given the likely lead time I'll be facing for the barrel, I'll be done with it by then.
ILya
Hopefully the price of brass goes down. As an AR cartridge saving every piece of brass like a bolt gun is pretty impractical. Be tough leaving 75 cents per round sitting on the ground. Hell right now it’s cheaper to buy loaded ammo from Hornady than it is to buy brass and a projectile.
I guess I am that guy.......
Don't get me wrong, I could give two fucks about what someone wants to purchase/push/suck-off........it keeps the industry going and brings in new innovation and new shooters.
Just don't piss and whine IF the new geewhiz cartridges are not in the winner's circle.......or living up to other expectations, whether those expectations are legit or not. Hell, yesterday I got a call back from a new cartridge shooter that I built a rifle for in a recently dropped new cartridge...….shoots great......1/4moa at 300yds......just can't get the velocity he was told without pressure signs...…..go figure. Contacted the cartridge "pusher"...….must be a tight barrel......again go figure.
Horsepower numbers sell cars......BC numbers sell bullets......and velocity and barrel life numbers sell cartridges...….nothing new here.
I hope the 6ARC (and others) come on scene and dominate......otherwise the R&D effort and investment were wasted......never a great business decision.
But I don't know shit about fuck
Ern
What gas system would be needed in the 6mmARC fir a 12.5” barrel? I know it’s running longer gas systems in the other lengths so I’m sure the 12.5” will need to be Mid-Intermediate? Thinking about a sbr in this but will definitely get a 18”-20” setup soon as I can.
Thanks for any info
Thanks for any info
Sorry if this is already answered. Will this use a type 1 or 2 grendel bolt? Also, will they feed direcrly from grendel mags without mods? Mahalo
Grendel 2 bolt. And yes unmodified grendel mags. Elander and ASC have been good so far
Proof Research is my first choice. Only 16 and 18" available right now but I bet more will be added soon. It looks like many of the upper tier 6 ARC rifles are being built around these. I would like to see real world numbers on a 22". (I know 6mm Grendel has already been done but similar =/= same.)
JP and others must already be working on options. Hasn't even been a week yet...
As for built to order outfits, I haven't seen anything yet...
I was not able to find Proof 6mm ARC barrels for purchase (I see the 18" on their site, which is what I'm interested in as a first barrel, but I don't see any way to purchase directly from them). I'd consider purchasing one if I could find a place to do so, do you have a vendor with inventory you'd suggest?
Ah, I see you meant available to ship now not purchase and wait. No such luck.
Currently only pre-order -> Altus Shooting Solutions.
I’ve always had a great experience with Altus, but their preorder indicates a November 2nd availability. Seems like Proof is taking time to get these out to the public. I’ll have to find another direction to go. Thanks for the tip, though!
Quick chat with JP indicated that they had been testing for a few weeks but were not ready to announce anything. Got the "stay tuned" response which at least sounded encouraging. But I have not found any other name brand precision focused barrels in the 20" to 24" range anywhere yet. I am probably asking too much in too short a time frame (for sure) but this has my interest and I have a great lower setup already built up.
I had thought proof announced some kinda partnership specifically for the ARC with an AR mfg. But obviously you can still order the barrel. Let me see if I can find it.
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Anyone have any guesses of what kind of velocities the 6mm ARC might be able to achieve with hand loads and a 26" barrel in a bolt gun? Wondering just how close it might be able to get to a Dasher.
I get 2850 out of a 22" 6mm predator AR with 90 gr sierras trying to keep it somewhat tame, so I would guess a 26" bolt gun could do damn near 3k with a 90gr bullet. The predator has a tiny bit more capacity though, its a straight neck down, no shoulder push back, of the grendel.
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24" barrel with 108's and XBR8208 will get 2750 @60ksi. Might get close to 2800 in a 26. With leverevolution you lose some temp stability but can get 2800-2850 in a 26" barrel at 60ksi.
I have a bunch of IMR 4895 I need to get rid of. Should be close enough in burn rate to use.
Given the bolt issues what would be the reasonable high pressure that the ar platform can hit and not worry about breaking bolts. Is 52k really the safe ceiling?
Well, my 18” Ballistic Advantage barrel showed up today. Anyone know of a place that has ammo in stock?
52001psi.
To get the same bolt thrust on a grendel/ppc variant as a .223/5.56 at max pressure you'd have to down load to 43-45ksi. So yes, 52ksi is probably the top.
6mm ARC Ammo
In-stock best prices for 6mm ARC Ammo | Best 6mm ARC Ammunition - AmmoSeek.com
ammoseek.com
I am thinking of getting the Odin 18 inch or the BA one! I see someone just got the BA how does it look? So curious how it shoots
Because the case would be terrible for long/slender 6mm bullets.
Look at (6.8 left, 6.5G right):
I’m actually looking forward to this cartridge and I hope it gets wide spread use. If you can say one thing about Hornady they go all in promoting new rounds. I like the 6mm bullet selection.
That said I just put set up and zeroed a 16” SS barreled upper to specificity run 77gr TMK loads. Suppressed target and predator hunting. Had I known this round was on the way I may have waited. An 85gr Game King HP out of the 6arc would be a great calling coyotes round and capable for other stuff.
That said I just put set up and zeroed a 16” SS barreled upper to specificity run 77gr TMK loads. Suppressed target and predator hunting. Had I known this round was on the way I may have waited. An 85gr Game King HP out of the 6arc would be a great calling coyotes round and capable for other stuff.
SAAMI max pressure on the 6.8 is 55,000psi (5.4% increase vs. Grendel variants). Doing some quick doodling in SolidWorks, if you shorten the 6.8 case to the same length as the 6 ARC, give it a 30 degree shoulder, same body taper as 6.8 SPC (magazines), and neck it down to 6mm, it has ~10-15% less internal volume than the ARC. I don't think you're going to match the ARC's performance with the 6.8 case.
Talked to Lantac yesterday. Said they should have rifles up on the website for sale later this week
2 Locations with Ammo per AmmoSeek this morning all 105 and 108's. Brownell's is one of them. Decent price for factory if you wanted to get started that way.
For most of my shooting I'll stick to 90-103gr pills more than likely - hunting mostly less than 350 unless I head to Western counties, where it's possible to stretch the shots on critters a bit more - usually a choice though so I can prepare beforehand.
Yes a shorty 6.8 could do fine with in those ranges....hahaha
Yes a shorty 6.8 could do fine with in those ranges....hahaha
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It has already been done about 6 years ago (TAC6 & the TAC30) and the 6.8 cases will handle 60k handloaded of course. It is a 6mm Herrett for all practical purposes so the shoulder has been blown out to .410", case length was shortened to 1.570". It does match the velocity of the 6mmARC.
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I may build a 6mm ARC with a longer barrel (18-24”) to take advantage of its ballistics in an AR-15 platform. I like the cartridge albeit not much load data out there yet.
The key items for me are:
Good Lower
Good Lower components
Timney trigger
Good compatible upper with an excellent barrel
Scope and mounts for the caliber’s capability
Stock with a good cheekweld
The key items for me are:
Good Lower
Good Lower components
Timney trigger
Good compatible upper with an excellent barrel
Scope and mounts for the caliber’s capability
Stock with a good cheekweld
But at 1.570” trim, you’re still stuck single loading the long, high BC bullets the same way we have been in the other Grendel variants, and at 60kpsi, the bolt thrust is actually greater than that of the Grendel based cases at 52000. That’s why the ARC was pushed back 30thou, and why it gives up the speed it does to the 6mmAR or 243LBC. No free lunches - there’s no replacement for displacement. A smaller case has to run commensurately higher pressure to achieve the same performance.
If the brass and bolt can hold up to 60k for the long haul then you'll be fine, but that remains to be seen from the info I've found with the 6ARC
What’s the likelihood of handloaders exceeding 52ksi because “they didn’t see pressure signs” not knowing they were affecting the fatigue life of the bolt?
Is 52ksi based on the bolt or the extension lugs or the case?
Not much we can do if it’s the case but if it’s the bolt, this may be the opportunity to utilize more modern materials than carpenter 158.
Is 52ksi based on the bolt or the extension lugs or the case?
Not much we can do if it’s the case but if it’s the bolt, this may be the opportunity to utilize more modern materials than carpenter 158.
Already been done. 9310 bolts are available, personally I'd run Constructor's Titan bolt if he is going to use it for this. Much stronger design and likely what would be needed to get longevity at the performance and pressures stated by LedZep. From what I'm aware of anyway, been a while since I've looked at anything Grendel related
I don’t see 9310 as that significant of an upgrade to 158. I was thinking more along the lines of more aermet series. I think LMT used to make 7.62x39 bolts out of that.
1.57 leaves no free bore for 105-110gr projos. And I don't see a big ammo maker (or many AR makers) making the SAAMI MAP 5000psi over the 6.8spc.
ETA: Just seen that CIP has the 6.8 at 58,700psi.
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