Ok I get that I am not on the cutting edge of all that is going on in the firearms world, I got a lot of grass and ferns to mow. I was sorting some range brass tonight and I found two pieces of brass that at first glance I was sure was identical. but I was wrong, one was 6mm arc and the other 6 Grendel. I do not see enough difference to go to the trouble of making a different chambering, they are so close to the same why would anyone bother??? Is there something I am missing? If so please explain???
6 ARC V 6 Grendel
- Thread starter ebb
- Start date
Nope, they're really close, as is a ppc. I prefer the Grendel due to lapua brass but it's scarce right now.
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Ledd Slinger
Silver $$ Contributor
They are basically the same thing. The 6mm ARC is one of Hornady’s marketing schemes where they take existing designs from wildcatters, slightly tweak it, give it a new name, act like they are testing it for the first time, then sell it to the general population who doesn’t know any better. Gotta give it to Hornady, they are great at marketing to the masses that are lesser educated in the shooting world.
Hornady did a good job in conjunction with Sturm Ruger on the 375 Ruger case design back in 2007. Of course, wildcatters immediately started necking the case down to 338, 308, 7mm, and even 6.5mm and tested them extensively. Later Hornady launched the 300 PRC as something brand new, but it was actually nothing new to wildcatters because it’s just a 375 Ruger case necked down to 30 cal.
The 6.5 PRC was a fairly independent design by Hornady because nobody I’m aware of had taken the 375 Ruger case and shortened that far prior to that. But as for the 6mm ARC, Hornady just copied what was already out there.
Hornady did a good job in conjunction with Sturm Ruger on the 375 Ruger case design back in 2007. Of course, wildcatters immediately started necking the case down to 338, 308, 7mm, and even 6.5mm and tested them extensively. Later Hornady launched the 300 PRC as something brand new, but it was actually nothing new to wildcatters because it’s just a 375 Ruger case necked down to 30 cal.
The 6.5 PRC was a fairly independent design by Hornady because nobody I’m aware of had taken the 375 Ruger case and shortened that far prior to that. But as for the 6mm ARC, Hornady just copied what was already out there.
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Jerry Wick
Silver $$ Contributor
The main difference is in the body length and neck length.
The body length of the 6ARC is 0.045" longer than a 6PPC.
The body length of the Grendell is 0.075" longer than a 6PPC.
The base and shoulder diameters of the three are more or less the same.
The body length of the 6ARC is 0.045" longer than a 6PPC.
The body length of the Grendell is 0.075" longer than a 6PPC.
The base and shoulder diameters of the three are more or less the same.
Larry Koch
Silver $$ Contributor
If no one has figured it out yet. You can take Starline 6mm arc brass size it in a PPC die. Neck turn it to your neck . It will come up a little short in length. Resize it, clean and load, and shoot at a match no fire forming necessary. For .40 cents each. They have lasted me more than 5 firings. And I dont feel like I'm married to it. Never have to Neck trim. By the time it gets that long it's finished.
Note the priming hole is standard size not the small 1.5mm. does it make a difference? I dont know for sure yet. I will say Hornady brass is not up for the task.
I would just as soon shoot lapua brass, but for some reason that is getting harder to find.
However I wonder if somone could convince Starline to punch or drill smaller primer holes.
Note the priming hole is standard size not the small 1.5mm. does it make a difference? I dont know for sure yet. I will say Hornady brass is not up for the task.
I would just as soon shoot lapua brass, but for some reason that is getting harder to find.
However I wonder if somone could convince Starline to punch or drill smaller primer holes.
Ledd Slinger
Silver $$ Contributor
Or you can reverse that and take PPC brass, jam a bullet in the lands and fire form it to 6mm ARC or 6mm Grendel.
I made a lot of 6mm LBC Turbo 40 brass from PPC cases back before the Grendel came along and had brass in production. Now I use Lapua 6.5 Grendel brass to make my cases.
Larry Koch
Silver $$ Contributor
So maybe you can get 220 Russia brass? If so where? Norma is not my thing.
Ledd Slinger
Silver $$ Contributor
No idea where to get it. I stockpiled a lot of brass over the years so I haven’t had any reason to look for more
It should do. Lots of experimenters have proven over the years that opening the 1.5mm (0.059-inch) flash-hole on 6BR / 220 Russian / PPC etc up to 70 thou' or more sees precision and velocity spreads deteriorate. There's a reason why those small 1960s precision numbers were given the small primer / small flash-hole combination and why this format has succeeded up to and survived to today, getting on for 60 years.
Likewise, Lapua exhaustively tests different formats of its new products under development and goes for what gives the best results. Again it's no accident that Lapua 6.5X47mm, Grendel, SP versions of the Creedmoors and the 308 Win SP 'Palma' cases have all been given 1.5mm flash-holes. Although not a betting man, I'm so sure Lapua will use this formula again on 6GT brass when it eventually appears that I'd risk a few pounds on this.
As stated by others, there is some "Marketing Gamesmanship" with doing a minor tweak to an existing cartridge and then treating it like a proprietary endeavor. Now you get to Name It and Trademark It. This has happened enough that it has become somewhat common (recent example: 300 Whisper vs 300 Blackout). That aside, the 6ARC brings more attention to the Grendel family from both the shooting community and manufacturers. This means more options and more product availability. I like the 6mm Grendel, but I bought a 6ARC for AR15 just for the availability of components as well as readily available off-the-shelf ammo (someday).
Aside from the "Marketing" angle, there is some merit to the argument around safety / liability. I am assuming this safety risk and product liability weighed heavy into the design modifications of the case. There are some hard lessons about cartridges that share the same parent case and have similar dimensions. The .223/5.56 and 300BO comes to mind. . In theory, with the 6ARC case length being shorter at the shoulder then a 6.5 Grendel case will be too long in the body to allow the bolt to close.
I believe that Hornady's case dimensions for the new 22 Grendel is same as the 6.5 Grendel. Without having tested this, I am assuming that the 6.5mm bullet diameter, regardless pf bullet ogive, prohibits a 6.5 Grendel case from being loaded into rifle chambered in 22 Grendel.
Aside from the "Marketing" angle, there is some merit to the argument around safety / liability. I am assuming this safety risk and product liability weighed heavy into the design modifications of the case. There are some hard lessons about cartridges that share the same parent case and have similar dimensions. The .223/5.56 and 300BO comes to mind. . In theory, with the 6ARC case length being shorter at the shoulder then a 6.5 Grendel case will be too long in the body to allow the bolt to close.
I believe that Hornady's case dimensions for the new 22 Grendel is same as the 6.5 Grendel. Without having tested this, I am assuming that the 6.5mm bullet diameter, regardless pf bullet ogive, prohibits a 6.5 Grendel case from being loaded into rifle chambered in 22 Grendel.
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So far load data offered has been over looked, in the differences in the two cartridges. this & BC of bullets that are truly compatible for the cartridges in the intended platform set the cartridges apart in my mindset, at least.
No properly supported Bolt action load data exist for the 6.5 Grendel with Sammy blessing. Seems Bill Alexander primary intended on 6.5 Grendel to be shot from a AR platform that offers marginal case head support. In the AR platform Each Cartridge is intended to be loaded at 52 K pressure or less for the AR platform.
Major difference here is Hornady allowed for separate load data for the more robust bolt action applications. The bolt action Sami pressure limitation for 6mm ARC bolt action application jumps to 62 K. Now add sleeker higher BC bullet offerings to the table of applicable bullets & 6mm ARC gains some ballistic & terminal advantages at distance.
Ballistically speaking, a few bullet offerings sure do make it more appealing but the lack of powder in the small case causes the loss for velocity and energy quickly (with both cartridges). The Match Burners, A Tips and Nosler RDFs look very impressive for 6mm bullets for sure. More so for a case capacity that can hold 50 grains or more of powder. The Grendel and ARC have limited uses but the upper end weights of the 6mm bullets fit well within the acceptable class for the ARC making it a better candidate for longer range accuracy battling the elements and bullet drop. I still love my Grendel since fairly recently building it. Considered the ARC but chose the Grendel. It'll be my short range lightweight woods deer rifle (100 yards).
SD, are you saying Hornaday created a whole new cartridge just so bolt action shooters could shoot at higher pressures? It never occurred to me to ask for Hornaday's permission when working up a load. And who would not feel safer using Lapua brass over Hornaday's? I guess I am just way behind the times, I thought any and all 6 or 6.5 issues were solved by the Creedmoor. Brass that was tough and bullets that don't blow up on the way to the target would have won me over, not marketing glitz.
Agree! The ARC is a valuable addition / option for the USA's many AR-15 platform shooters who want to extend their ranges on non-living targets. Where I am (UK), we're not allowed semi-autos, and the larger area Grendel/ARC case-walls make for harder extraction than the 223 on our manual (side-handle straight-pull) versions, so less of a plus for us here.
For anybody with a small bolt-action with the correct bolt-face (Howa Mini, Cz527 etc), the ARC makes a nice, low recoil number with long legs, but for most people building on the much more common 0.473" bolt-face actions, the 6BR, Dasher, BRA, 6GT and goodness knows how many other larger cased sixes have got to be better for any competition use. I have a 6.5G Howa Mini in an Oryx stock, and it's a lovely little low-recoiling plinker for range use, but very limited utility otherwise. I had thought of replacing the factory barrel with something both heavier and higher-grade, alternatively changing to the ARC, but decided against - as you say the small case / powder charge sizes are just too limiting. In continental Europe, where many target shooters are limited to 300-metre ranges, there might be possibilities, but with competitors wedded to the hugely successful and flexible 6mm BR Norma, why change? (They wouldn't for the 6.5X47mm Lapua which was originally designed as a 300M ISSF competition cartridge.)
There is some deerstalking Grendel use in the UK and Europe, where it's well suited to the small Roe species, our native deer, but it's a tiny minority compared to the number of 243 Win users and those shooting the larger 6.5s.
These little cases are great but they're being marketed to the cool kids right now, err, long range. Yes, they'll go bang with a 108 class 6mm bullet and yes, better than 556/223 performance, but they just lack raw capacity to shine their brightest with the heavy for caliber projectiles. They shine brightest with light bullets but if you're stuck on long range and nothing else turns your crank, run the numbers yourself of 87-95 grain bullets vs 105-108 grainers. I can push 95's at 3100 from a straight 6 Grendel in a good BOLT gun. Run the numbers and see what the drift difference is based on that vs the heavies and generally, shorter bullets have better all out accuracy potential than longer ones. The tradeoff is bc but you can't push the heavies fast enough to benefit from them in these cases. Step up to a bit bigger case and horsepower starts to favor the heavies, by a little bit.
Ledd Slinger
Silver $$ Contributor
True, but this thread is comparing the “6mm” Grendel to the 6mm ARC. You can build any Grendel on a bolt rifle and start working loads up while watching for pressure signs just like we do everything else. I honestly have never given load data in manuals much credence. I only use it as a quick reference for starting points on loads with different powders, then I’m off recording all my own data after that. The pressure lies where I find it. Sometimes that can be sooner than what the manuals state too. Just depends on the barrel and chamber.
Like I said, I love my but know it's limits. It's easily a 400 yard deer rifle but why bother worry about that percentage of possible bad outcomes from it. I have half a dozen better 6.5 options in my safe. There cool guns for sure and recoil is just a bit more than a 223 with 80s.
Ledd Slinger
Silver $$ Contributor
That’s not the subject either
Nope it's not but IF I owned a 6ARC, my response would have been the same. Virtually identical performance within any given range. Pick your pleasure.
I like to "micro" calibers. The Grendel family is great in an AR15, but the cartridge shines when chambered in a bolt rifle. The difference between a 243 Win or 6 Creedmoor and a 6ARC with similar bullet weights is 400fps - 500fp, and even less if chambered in bolt rifle. Yes, the velocity difference is significant but not necessary for typical hunting distances. New bullet technology has further narrowed the difference in terminal effect. Shooter's skills are the deciding factor.
The other factor to consider is barrel life. Outside of F-Class competition, those of us who shoot a lot can benefit from the much longer barrel life realized in the slightly smaller Grendel-class cartridges. If you don't need max velocity for long range (600yard - 1000 yard) then you can shoot a Grendel variant with 2x-3x barrel life of a Creedmoor. If I need a little more gas then maybe a BR variant or something bigger.
I think of it as an excuse to buy or build one of everything.
The other factor to consider is barrel life. Outside of F-Class competition, those of us who shoot a lot can benefit from the much longer barrel life realized in the slightly smaller Grendel-class cartridges. If you don't need max velocity for long range (600yard - 1000 yard) then you can shoot a Grendel variant with 2x-3x barrel life of a Creedmoor. If I need a little more gas then maybe a BR variant or something bigger.
I think of it as an excuse to buy or build one of everything.
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