6MM ARC

[woodline]

The magazine issue does leave me a bit irked.. lets hope that Magpul gets on the Schick with it.

Besides not wanting to get into another cartridge, the two things that have held me back from 6.5 Grendel are the lack of good standard capacity magazines and the thin walls of the bolt on an AR chambered in it.

Which is a shame because I think it is a fantastic cartridge. The steel cased ammo availability is huge, and its ability to perform well from a 12" barrel all the way up to a 24" barrel is really cool.

 

[holesonpaper]

Although I'm not a fanboy, there's clearly some momentum starting for this round. Personally I'm fine being a slow(er) adopter.

https://www.shootingillustrated.com/articles/2020/6/9/barrett-ships-6-mm-arc-rifles-to-dod/

 

[Speed3]

Here is some ballistic info comparing the 6mmARC vs 6.5 Grendel vs .308 with real world data.

Interesting that the 6mmARC carries more energy at 400 yards than the grendel. It also bucks the wind better in the comparison. Some of you grendel shooters, check those 6.5G ballistics and see if they are reasonable.

https://www.youtube.com/watch?v=kLqP5lglgKo

BTW...all the videos I've seen shows it being fed from a mag flawless. Although most have loaner rifles and probably would edit any fails out of the video lol.

 

[Surt]

Here is some ballistic info comparing the 6mmARC vs 6.5 Grendel vs .308 with real world data.

Interesting that the 6mmARC carries more energy at 400 yards than the grendel. It also bucks the wind better in the comparison. Some of you grendel shooters, check those 6.5G ballistics and see if they are reasonable.

https://www.youtube.com/watch?v=kLqP5lglgKo

BTW...all the videos I've seen shows it being fed from a mag flawless. Although most have loaner rifles and probably would edit any fails out of the video lol.

6mm had been taking over the PRS scene that has been held by the 6.5mm for awhile. It's all about cross-section and bearing surface, and people are learning really quickly how to game these systems to provide really slippery bullets at increasingly smaller diameters. It's mind-boggling that we're now looking at 108gn 6mm bullets when it wasn't all that long ago that bullets almost a full millimeter (or even two!) were not all that much heavier.

 

[Mike3888]

6mm had been taking over the PRS scene that has been held by the 6.5mm for awhile. It's all about cross-section and bearing surface, and people are learning really quickly how to game these systems to provide really slippery bullets at increasingly smaller diameters. It's mind-boggling that we're now looking at 108gn 6mm bullets when it wasn't all that long ago that bullets almost a full millimeter (or even two!) were not all that much heavier.

Can’t go wrong with any 6mm no matter what it’s chambered in. Wish I had all the money back in 6mm bullet I’ve sent down range.

 

[DavidA]

Okay here are the ballistics from StrelokPro 6 ARC in 108 gr Hornady Match , 2,750 fps from a 24” barrel. At sea level. I will give you speed, energy, drop in mils 200 yd zero drift in mils 10 mph cross wind.

Muzzle 2,750 , 1812 ft lbs
400 yds , 2,122 fps, 1,080 ft lbs, 1.5 mils, .72 mils
1,000 yds. 1,337 fps, 429 ft lbs, 8.9 mils, 2.16 mils

Okay the champion 264 LBC ( BHW barrel) 24” 130 gr RDF

Muzzle 2,624 fps , 1,988 ft lbs , NA, NA
400 yds 2,082 fps, 1,252 ft lbs, 1.6 mils, .66 mils
1,000 yds, 1,389 fps, 558 ft lbs, 9.1 mils, 1.92 mils

I can refer you to the 6.5 Grendel forum to verify the Grendel’s performance suggested above.

http://www.65grendel.com/forum/show...wer-pro-varmint/page2&highlight=130+gr+Berger

So based on the above Grendel is better than ARC. At 1,000 yds, 52 more fps , 129 ft lbs more energy, .24 less drift. You can even shoot a 140 gr RDF at 2,480 , drop at 1,000 is 10.0 mils with a 1.91 drift. So other than having 13 more ft lbs of energy there is no advantage gained by going to a 140 gr bullet.

So other than a little less recoil the Performance of the Grendel is pretty much at least equal if not a little better than the 6ARC. Actually you find it hard to slide a piece of paper between the performance of both these cartridges. So Hornady is betting on the fact that they can provide match grade AMMO in a package people want to use. 6 mm is definitely coming on strong and Hornady is going to move it on. But there is no performance advantage over the Grendel.


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[Speed3]

Thanks for confirming 6.5G info.

You can load a 130gr rdf to 2.260(max AR mag length)? I was reading the 123gr was about max for mag feeding?

I just placed an order for a 20" 6mmARC. I don't expect to see 2750fps, in reality it will be around 2600 fps. From what I looked at the 6mmARC edged out the 123gr 6.5G in 20" in AR form. I don't really see the benefit to 6mmARC in a bolt gun. 6CM beats the pants off it in the short action and the 6x47L also.

 

[DavidA]

Thanks for confirming 6.5G info.

You can load a 130gr rdf to 2.260(max AR mag length)? I was reading the 123gr was about max for mag feeding?

I just placed an order for a 20" 6mmARC. I don't expect to see 2750fps, in reality it will be around 2600 fps. From what I looked at the 6mmARC edged out the 123gr 6.5G in 20" in AR form. I don't really see the benefit to 6mmARC in a bolt gun. 6CM beats the pants off it in the short action and the 6x47L also.

Yes you can even load 140’s to mag length. The Powder they are getting this velocity out of is Power Pro Varmint


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[lazarus]

If I want to be a jerk, I’d like to point out the 6.5G isn’t slightly better for hunting. It’s a lot better. Slightly more energy, but you are also delivering 20% more surface area for the wound channel and comparable sectional density comparing a 108 to a 130gr.

That’s more than a slightly increase in terminal performance.

 

[DavidA]

Yes 6.5 Grendel over 6 ARC all day for hunting .


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[DavidA]

When Whitley came out with the 6mm AR and then subsequent copies 243 LBC. Etc I was tempted to get a Predator Barrel from ARP . However, when you put it all down on paper, there really is no justification other than I want a 6 mm AR.


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[Speed3]

If I want to be a jerk, I’d like to point out the 6.5G isn’t slightly better for hunting. It’s a lot better. Slightly more energy, but you are also delivering 20% more surface area for the wound channel and comparable sectional density comparing a 108 to a 130gr.

That’s more than a slightly increase in terminal performance.

I've got other guns for hunting, that is not the main purpose for MY build. However there have been MANY deer and smaller animals killed with 6mm rounds over the years, cant deny that.

As with anything knew... lots of skepticism, but this round fits right in my wheel house. I already have the powder and bullets in large quantities so this one worked for ME.

Don't worry I'll post my journey of finding the load and hiccups along the way.

 

[Speed3]

When Whitley came out with the 6mm AR and then subsequent copies 243 LBC. Etc I was tempted to get a Predator Barrel from ARP . However, when you put it all down on paper, there really is no justification other than I want a 6 mm AR.


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If you already have a 6.5G, 1000% agree. No way I'd make the move, although really its just a barrel swap, uses same bolt face and mags.

For someone like me, that goes through lots of heavy 6mm...easy decision.

 

[DavidA]

If you got the components so it. Beside nothing wrong having a different flavor.


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[Speed3]

I.got my hands on some 6mmARC and pulled a round. Any idea what ball powder this is?

My barrel isn't done yet, so I can't test fire yet

I double checked the powder charge on a scott parker scale, might be 30.4gr vs the charge master 30.3gr.

 

[dbledoc]

I am going to resurrect this thread.
I am currently considering building an upper in 6 mm ARC and was wondering what the collective experience is?

I am looking at long range >800 yard target shooting in an AR 15 sized rifle. I have a 6.5 Creedmore and 308s.

 

[4g64loser]

I am going to resurrect this thread.
I am currently considering building an upper in 6 mm ARC and was wondering what the collective experience is?

I am looking at long range >800 yard target shooting in an AR 15 sized rifle. I have a 6.5 Creedmore and 308s.

Call LBW shooters supply down in virginia. Louis Wood. I've shot guns he has built for. Highly recommend. He was up for match last year and brought a few of his rigs. In calm conditions we were making 949yd headshots. He has had his hands in the long range, non 556, ar game for a long time.

Another guy who builds PRS oriented gasguns is drew walters at WAR rifles in manassas park. I don't own any of his gasguns but I've seen him shoot a creedmoor gasgun and whip guys with solid bolt guns. I do own one of his boltguns and it is a great shooter.

 

[calicojack]

6.5 Grendel baby!