https://www.hornady.com/6mmARC#!/

As a fan of 6mm bullets, good to see Hornady offering this. 6MM 105 grain class bullet at 2700-2750fps out of a efficient small case, not bad!

Over the last several years guys around me have been shooting similar calibers such as Robert Whitley's http://6mmar.com/

I saw that and my immediate response was, “Damnit! Am I finally going to get sucked into 6mm?”

Unfortunately driving to the Chaffee range is becoming less desirable all the time. Our local club is claiming that its 600 m/y range will be usable by this fall. Keeping my fingers crossed.

quote:

Originally posted by sigfreund:
I saw that and my immediate response was, “Damnit! Am I finally going to get sucked into 6mm?”

Suppressed 6mm ARC 12.5" SBR, Sierra 95TMK at 2650 would be perfect for you!

Yep, when 5.56 or 6.8 or 6.5 Creedmore just won't do:

https://www.thefirearmblog.com...dod-6mm-arc-program/

The 6 ARC may end up being a well supported viable option. My only real question is that it is a longer range option for a weapon type that I won't likely be using for longer range shooting. At short to mid range the 6.5 Grendel is going to have more energy. Are those the ranges I'd be using it?

Compared to the 6.5 Grendel/264 LBC the 6mm ARC is likely to have FAR more commercial support and that is likely to make the real difference vs minor ballistic comparisons 6mm vs 6.5

The 6mm ARC has a lot of potential. Fires from a 5.56 sized AR with only a barrel and bolt change (6.5 Grendel bolt) from a standard lower. That means any AR owner can buy a drop-in precision upper.

With long, high-BC bullets that are heavier than the heaviest 5.56, 6mm ARC remains supersonic past 1000 yards, increasing long range accuracy significantly by avoiding the buffeting during the transition to subsonic velocity.

Longer range, better accuracy, flatter trajectory, better terminal performance, with a mild increase in recoil, loss of only 5 round capacity (25 vs. 30) and without the increased weight or expense of a .308 AR platform.

Seems like they found the sweet spot for a mini-Creedmore.

I have often wondered if something like a 6 Grendel or 6 SPC (.244 Valkyrie?) would be commercialized. Given the recently-introduced Valkyrie, I figured the SPC would be the parent case.

IMO all of the commercialized AR15 wonder-cartridges have experienced teething problems upon introduction. I will sit back and see what surfaces....
- Will actual MV meet expectations in barrel lengths used by most shooters? MV needs to be high enough to push the heavy-for caliber bullets that offer the best BCs.

- Will accuracy be good for different barrel makers and reamers?

- Will the ammo manufacturers produce accurate loads from the start?

quote:

Originally posted by offgrid:
https://www.hornady.com/6mmARC#!/

As a fan of 6mm bullets, good to see Hornady offering this. 6MM 105 grain class bullet at 2700-2750fps out of a efficient small case, not bad!

Over the last several years guys around me have been shooting similar calibers such as Robert Whitley's http://6mmar.com/

How is it any different/ better than the exceptional Lapua brass offered for the 6mm Creedmoor? Is it just because it is commercially loaded? I can't find anything on case capacity online.

Isn't the military playing with replacing the 5.56 NATO with a 6.8mm cartridge (SIG or other)? Since this was developed for the Army, where does this fit in with that program, if at all. If they're looking to get away from the AR platform, why are they looking for a new round to shoot out of the AR platform?

quote:

Originally posted by 280nosler:

How is it any different/ better than the exceptional Lapua brass offered for the 6mm Creedmoor? Is it just because it is commercially loaded? I can't find anything on case capacity online.

The HUGE difference is that the 6mm ARC fits into a standard AR-15 frame whereas the 6 Creedmoor requires an AR-10 Frame.

The 6 ARC is basically a 6mm Grendel with a slightly shortened shoulder and enough case differences they don't have to pay Alexander Arms for the Grendel name. It's a whole different ball game than a 6mm Creedmoor.

quote:

Originally posted by fritz:
I have often wondered if something like a 6 Grendel or 6 SPC (.244 Valkyrie?) would be commercialized. Given the recently-introduced Valkyrie, I figured the SPC would be the parent case.

IMO all of the commercialized AR15 wonder-cartridges have experienced teething problems upon introduction. I will sit back and see what surfaces....
- Will actual MV meet expectations in barrel lengths used by most shooters? MV needs to be high enough to push the heavy-for caliber bullets that offer the best BCs.

- Will accuracy be good for different barrel makers and reamers?

- Will the ammo manufacturers produce accurate loads from the start?

As I mentioned above several guys shooting 6mm Grendel wildcats here in Colorado for many years. Robert Whitley introduced the 6mmAR (6 Grendel) 10-12yrs ago for High Power, not a new caliber. I've seen excellent accuracy out of 6 Grendels at matches. 22" barrel Berger 105 Hybrids at 2750fps. The 6mm ARC has the shoulder pushed back a little over the Grendel. May or may not have an effect on velocity.

Reamers. I'd wager you can call JGS today and order a reamer. Also wager they'll know what freebore to use for Berger 105's.....

Another common 6 Grendel wildcat is the 6MM Grinch, 40 degree shoulder. Same as the 6mm FatRat and Whitley's 6mm Turbo. Do a search on the 6mm Grinch, does very well in BenchRest, rivals the 6PPC. Craddock offers 6mm Grinch Bartlein AR barrels, no doubt they'll soon offer ARC barrels.

This message has been edited. Last edited by: offgrid,

What would be more useful would be a round in the 6-6.5mm range that would be mag and bolt compatibile (meaning only a barrel change) with 5.56mm. Or is this .224 Valkyrie?

Interesting reading on the existing 6mm variants -- Whitley, et al.

I will definitely follow what develops over time. I have considered Grendel, Valkyrie, Nosler, 6.8SPC -- but all had certain drawbacks. It appears Wilson Combat will make a 6mm ARC upper, and I suspect Craddock Precision will eventually offer barrels. I already have enough uppers for one lifetime, but maybe another one in ARC might do.

I saw a chart of projected(?) 6mm ARC muzzle velocity for 108 ELD-M for various barrel lengths. The MV for the 20" barrel looks to be roughly 2650 fps. I'll use that for comparisons to my other rifles' ballistics at 7,000' DA at 600 yards.

My competition 20" AR15 with 73 ELD does 2800 fps. Drop and drift (10 mph crosswind) in MOA at 600 yards:
12.9 drop
4.4 drift

Predicted 6mm ARC with 108 ELD at 2650:
13.2 drop
3.4 drift
Thus, the 6mm ARC has about the same drop, but roughly 1/4 less wind drift.
Interestingly, these stats are really close to 224 Valkyrie with SMK 90 at 2650 MV, which is what I figured a 20" Valkyrie barrel would do for me.

My new 24" upper in 6CM produces 2900 MV with 108 ELD:
10.6 drop
2.9 drift
The better ballistics are expected, given the case capacity of the 6CM. And of course, in an AR10 platform.

The trusty 26" bolt action 6.5CM does 2820 MV with 140 ELD:
11.5 drop
2.7 drift

Always good to compare numbers! But, that doesn't tell us how well a bullet/caliber combo shoots. I shot my 6x47's 150-200 faster then the 6BRA. 6BRA easily shoots inside the 6x47's. Same thing can be said for the 6.5x47 vs 6.5CM.

Frank Green of Bartlien posted one of the guys in their shop put together a 24" 6mmARC gasser. With handloads zinging 105 at 2885fps, shooting tiny groups. Seems fast? Brass hold up at that pressure?