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Posted: 3/17/2020 2:26:49 PM EDT
I hadn't seen this posted here yet, but SAAMI added a 6mm Grendel derivative called the 6mm Advanced Rifle Cartridge or 6mm ARC to their newly accepted cartridges list.
6mm ARC SAAMI introduction The case looks like the shoulder has been moved back, and the neck is a little shorter as compared to a Grendel case. The published instrumental velocity shows 2,700 fps for a 108gr bullet. A poster on The Hide put up a picture of Hornady headstamped 6mm ARC brass, so it seems likely they are behind the introduction (which IMO is a good thing as they know how to run a cartridge rollout). Anyway, it's interesting to see a cartridge similar to the 6mmAR become SAAMI standardized, I think I'll definitely be picking up a 20"-22" barrel for a long range build when they become available. |
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Interesting- thanks!
The 6mm Creedmoor has been out a while. How does this new 6mm improve on the performance of the 6mm Creedmoor or the 243 ? |
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Interesting- thanks! The 6mm Creedmoor has been out a while. How does this new 6mm improve on the performance of the 6mm Creedmoor or the 243 ? View Quote |
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Quoted: https://thumbs.gfycat.com/AdmiredFailingAnemonecrab-size_restricted.gif ASC makes several magazines that sometimes work! 5, 15, and 25 rounds View Quote |
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I won't give up my 6.5 Creedmoor as my long range go to, but I sure would appreciate a slightly more economical alternative (not that the Creedmoor is a bank breaker) with reasonable windage performance at distance. I shoot more reloads than factory ammo, but it is nice to have the option of buying off the shelf.
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I'm way out of the loop on Grendel stuff. How are the bolts holding up long term? I know there were some issues a long time ago but I assume there has to be a few solid options now.
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I'm way out of the loop on Grendel stuff. How are the bolts holding up long term? I know there were some issues a long time ago but I assume there has to be a few solid options now. View Quote I have yet to see a broken bolt personally in anything but 5.56 over 10,000rds. I know people have done it though. I would limit my sources for bolts to a few companies who have that dialed-in with their vendors. If I was hot-rodding the 6mm AR or any 6mm Grendel variant, I would prefer to use a bolt made of a unique aerospace grade alloy, with a different type of barrel extension set-up than a normal AR15. Running it at lower pressures, I wouldn't worry much about it. |
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I am a super 6.5 G fan. Sell tons of ammo and barrels at my shop. I had a customer come in last week with two lugs broken off of his Grendel bolt. Said he had a couple thousand rounds on the gun, all suppressed. I Don’t remember h name brand of the gun, but it was a factory Grendel. I installed an adjustable gas block and a new Faxon bolt, and got him all tuned up and back in action.
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I broke a couple Grendel AA factory bolts and had a buddy that broke a JP supplied bolt.
I was an early adopter. Recently, I haven’t had or heard of any trouble. |
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The barrel vendor who is "not to be mentioned on this site" has offered a 6 mm Grendel Wildcat for a while. I wonder how this 6 mm ARC compares with that round.
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The barrel vendor who is "not to be mentioned on this site" has offered a 6 mm Grendel Wildcat for a while. I wonder how this 6 mm ARC compares with that round. View Quote |
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Quoted: I believe that the 6mm Predator is the same as the 6mmAR. The shoulder on the 6mm ARC is moved back a bit from the 6mmAR (I'm guessing so 108gr ELDs will fit perfectly at mag length), so the ARC will have a bit less capacity and be a little slower. View Quote |
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I’m betting the minor change in dimension is so that it doesn’t fall into a trademark/patent issue. Would have been cool if they went the other direction, with a more blown out case, but the wildcats have already established those dimensions. View Quote View All Quotes View All Quotes Quoted:
Quoted: I believe that the 6mm Predator is the same as the 6mmAR. The shoulder on the 6mm ARC is moved back a bit from the 6mmAR (I'm guessing so 108gr ELDs will fit perfectly at mag length), so the ARC will have a bit less capacity and be a little slower. He is also listing the 6mm ARC barrel, no pricing as of yet though. Says the 6mm ARC is .023" more shallow than his 6mm Predator. |
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Quoted:I’m betting the minor change in dimension is so that it doesn’t fall into a trademark/patent issue. View Quote If you accidentally shoot a 6mm bullet through a 6.5mm bore it might be interesting, but no real problem. But try shooting a 6.5mm bullet through a 6mm bore.... |
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The minor change in dimensions resulting from shortening the brass to 1.490 vs Grendel at 1.520 is so that a guy can't accidentally load 6.5 Grendel into a 6mmARC chamber. If you accidentally shoot a 6mm bullet through a 6.5mm bore it might be interesting, but no real problem. But try shooting a 6.5mm bullet through a 6mm bore.... View Quote View All Quotes View All Quotes Quoted:
Quoted:I’m betting the minor change in dimension is so that it doesn’t fall into a trademark/patent issue. If you accidentally shoot a 6mm bullet through a 6.5mm bore it might be interesting, but no real problem. But try shooting a 6.5mm bullet through a 6mm bore.... I think there’s more to it. |
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Interesting theory, but there’s the 6.5 creedmoor and 6 creedmoor....260 and 243 I think there’s more to it. View Quote View All Quotes View All Quotes Quoted:
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Quoted:I’m betting the minor change in dimension is so that it doesn’t fall into a trademark/patent issue. If you accidentally shoot a 6mm bullet through a 6.5mm bore it might be interesting, but no real problem. But try shooting a 6.5mm bullet through a 6mm bore.... I think there’s more to it. The main reason for the differences is more optimal performance and placement of longer VLD-type bullet shapes in relation to the neck-shoulder junction, as well as optimal propellant burn characteristics with the 30° shoulders, nothing to do with trademarks or patents. |
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The case dimensional differences between .260 Rem and 6.5CM, as well as .243 Win and 6mm CM are considerable. The main reason for the differences is more optimal performance and placement of longer VLD-type bullet shapes in relation to the neck-shoulder junction, as well as optimal propellant burn characteristics with the 30° shoulders, nothing to do with trademarks or patents. View Quote View All Quotes View All Quotes Quoted:
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Quoted:I’m betting the minor change in dimension is so that it doesn’t fall into a trademark/patent issue. If you accidentally shoot a 6mm bullet through a 6.5mm bore it might be interesting, but no real problem. But try shooting a 6.5mm bullet through a 6mm bore.... I think there’s more to it. The main reason for the differences is more optimal performance and placement of longer VLD-type bullet shapes in relation to the neck-shoulder junction, as well as optimal propellant burn characteristics with the 30° shoulders, nothing to do with trademarks or patents. |
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Quoted: I’m betting the minor change in dimension is so that it doesn’t fall into a trademark/patent issue. Would have been cool if they went the other direction, with a more blown out case, but the wildcats have already established those dimensions. View Quote 99% sure shoulder was pushed back and neck shortened to properly fit long sleek 6mm bullets (probably specifically the 108gr ELD) at mag length. Same as H did with the Creedmoors and ~2.8 mags. Blowing the shoulder forward would have been counter to the obvious goals of this cartridge design. |
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2700 fps from what length barrel?
Virtually identical to Robert Whitley's 6mmAR cartridge. Lapua 90's or Sierra 95 grain match king's may help boost velocity in shorter barrels. |
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http://6mmar.com/images/6mmarturbox300__1_s2ts.jpg And the Turbo 40 vs 6mm AR http://6mmar.com/images/turbo_40_vs_6mmar__1.jpg The Turbo 40 can drive 105 gr projectiles at 2900 fps View Quote |
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2700 fps from what length barrel? Virtually identical to Robert Whitley's 6mmAR cartridge. Lapua 90's or Sierra 95 grain match king's may help boost velocity in shorter barrels. View Quote |
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Ummm...how much different is the case of a 6.5creed to a 6 creed? A 260 to a 243?? I think you missed the point being made about dummy proofing a round for chambers. View Quote View All Quotes View All Quotes Quoted:
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Quoted:I’m betting the minor change in dimension is so that it doesn’t fall into a trademark/patent issue. If you accidentally shoot a 6mm bullet through a 6.5mm bore it might be interesting, but no real problem. But try shooting a 6.5mm bullet through a 6mm bore.... I think there’s more to it. The main reason for the differences is more optimal performance and placement of longer VLD-type bullet shapes in relation to the neck-shoulder junction, as well as optimal propellant burn characteristics with the 30° shoulders, nothing to do with trademarks or patents. You can chamber a .308 in a .270 Winchester though, and fire it! Recoil will be impressive if the rifle holds together. The case will come out with no neck, just a hole at the end of the shoulder. |
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Is the 6mmAR a saami cartridge? View Quote |
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Quoted: I was only responding to the claims of patents and trademarks between all 4 of those cartridges, not whether one can be chambered in another. You can chamber a .308 in a .270 Winchester though, and fire it! Recoil will be impressive if the rifle holds together. The case will come out with no neck, just a hole at the end of the shoulder. View Quote Whether the approximate 20-30 thou difference optimizes seating a 108 vs going straight grendel or getting an extra 100-150fps by blowing out the case isn’t really a huge deal. The big news is there will be another cartridge available that will yield great LR performance from an AR-15 frame. It should be flatter than a 6.5 grendel with more energy than a 224Valkyrie. To those that think it’s crazy to patent a design, I think the AR Turbo 40 reamers and dies still have patents on them. Wasn’t the same true with the 6.5grendel upon inception, which is why some have the .264 LBC ? Designed to be compatible with 6.5grendel, but just slightly different. |
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Quoted: That wasn’t really what was being discussed among the 4 cartridges, but no worries. Whether the approximate 20-30 thou difference optimizes seating a 108 vs going straight grendel or getting an extra 100-150fps by blowing out the case isn’t really a huge deal. The big news is there will be another cartridge available that will yield great LR performance from an AR-15 frame. It should be flatter than a 6.5 grendel with more energy than a 224Valkyrie. To those that think it’s crazy to patent a design, I think the AR Turbo 40 reamers and dies still have patents on them. Wasn’t the same true with the 6.5grendel upon inception, which is why some have the .264 LBC ? Designed to be compatible with 6.5grendel, but just slightly different. View Quote I don't think it's crazy for someone to patent a derivative cartridge design, it's just not very smart. Folks who haven't dealt with IP, often think it's something it's not. A patent is only worth what you're willing to spend in court defending it. Who is going to spend millions of dollars in court defending a simple necked down Grendel, any why would they bother? All anyone has to do to get around it is change a few minute parameters a la the .264 lbc vs 6.5 Grendel. It was a dumb move to try to keep the 6.5 Grendel proprietary, and eventually BA opted to drop that of effort and had it standardized. There is a lot of prior art out there for straight necking down the 6.5 Grendel, I doubt anyone has a patent on it, and I that's why I don't think the shoulder on the ARC is pushed back 30 thou just to get around a patent, because it just wouldn't make much sense for that to be the case. |
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When I first wanted an AR variant I picked my ideal bullet weight and 6mm seemed to be perfect. At the time there was no "mainstream" 6mm AR cartridge and 6.5 Grendel seemed to be the best choice. I think the case would benefit from a lighter bullet while keeping high BC, so I hope this catches on.
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I absolutely love the 6.5 Grendel. I was an early adopter and chose it for my first AR as for me personally it was a great all-around job for me. It was a great long range target and could easily be used for hunting.
I'll most likely eventually pick up one of these as well. I love 6mm cartridges just as much as 6.5mm. Have always had a huge soft spot for the 6x45 with the seirra 95gr matchkings. This cartridge with those should be a heck of a lot faster! Even better now that there is a tipped matchking for the 6mm 95gr. |
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Once things calm down, I'll have one of these.
20" or longer would be great for yotes and target work. I've been saying for years that if someone brings the 6mm Grendel to SAAMI with big name weight and brass/ammo, it will be the ideal TGT cartridge for the AR15. Ballistics are nice, recoil is practically non-existent. 2.3 mils wind drift at 1000yds with the 105gr Berger Match Hybrid (.275 G7 BC) in 10mph full value wind at sea level, although not much energy. Will make a great NRA cross-course cartridge that can be mag-fed, and will hit steel hard enough out to 600yds. |
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Once things calm down, I'll have one of these. 20" or longer would be great for yotes and target work. I've been saying for years that if someone brings the 6mm Grendel to SAAMI with big name weight and brass/ammo, it will be the ideal TGT cartridge for the AR15. Ballistics are nice, recoil is practically non-existent. 2.3 mils wind drift at 1000yds with the 105gr Berger Match Hybrid (.275 G7 BC) in 10mph full value wind at sea level, although not much energy. Will make a great NRA cross-course cartridge that can be mag-fed, and will hit steel hard enough out to 600yds. View Quote |
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I've built two 6MM grendel/243LBC AR's now and they are quite a bit more accurate than my 6.5 Grendels that I also have. I have a 20" Bull barrel and a 24" bull barrel rigs.
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Well that's neat.
Last summer I was close to rebarreling my Howa mini to 6.0 Grendel but kept getting distracted with other stuff and wasn't excited about getting into the wildcat game anyways. Going to give this a real look when stuff really comes out for it. |
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I have the 6x45 and love it best I can do is an 87 grain Berger thing is dead on sick but I have not tried anything heavier just wont feed anyway but the cartridge is awesome and I would not mind trying a 6mm Grendel but when this stuff going on flys over
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Wonder what an 80 tsx or a 55bt will do out of it? Could be a sweet coyote/deer round for hunting.
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Quoted: Once things calm down, I'll have one of these. 20" or longer would be great for yotes and target work. I've been saying for years that if someone brings the 6mm Grendel to SAAMI with big name weight and brass/ammo, it will be the ideal TGT cartridge for the AR15. Ballistics are nice, recoil is practically non-existent. 2.3 mils wind drift at 1000yds with the 105gr Berger Match Hybrid (.275 G7 BC) in 10mph full value wind at sea level, although not much energy. Will make a great NRA cross-course cartridge that can be mag-fed, and will hit steel hard enough out to 600yds. View Quote Same. I just can't bring myself to fiddle around making brass. Off the shelf brass is my sink or swim. |
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Someone posted this up on the Hide:
http://pacifictoolandgauge.com/hornady/20193-hornady-tc25166-6mm-arc-fl-rougher-company-only.html http://pacifictoolandgauge.com/6-mm-69-mm-chamber-reamers-nopix-/20230-6mm-arc-advanced-rifle-cartridge.html Maybe we're getting close to the roll out. |
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I'm cautiously in...
Interested to see how fast you are going to be able to launch the Hornady 103gr ELD-X out of 16" and 18" barrels with it. |
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School me on the advantages of shooting these 100gr long flechette dart-type 6mm bullets out of carbine barrels inside 200/300 yds.
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Quoted: School me on the advantages of shooting these 100gr long flechette dart-type 6mm bullets out of carbine barrels inside 200/300 yds. View Quote When a bullet that is long-for-caliber (LFC) tumbles it creates a nastier slash than a shorter bullet. Important for shorter barrels in 6mmARC. When a bullet that is LFC mushrooms, its mass and momentum drive it deeper. Important for shorter barrels in 6mmARC. When a bullet that is LFC fragments, its greater mass creates more fragments and the larger chunks are driven deeper. Important for shorter barrels in 6mmARC. You seen the VIDEO of a 6.5 Grendel Hornady 123gr ELD blasting a huge wound channel like a beast? |
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Quoted: I was only responding to the claims of patents and trademarks between all 4 of those cartridges, not whether one can be chambered in another. You can chamber a .308 in a .270 Winchester though, and fire it! Recoil will be impressive if the rifle holds together. The case will come out with no neck, just a hole at the end of the shoulder. View Quote I shot a handful of 5.56 out of a 6x45......accuracy was horrible..........the necks were split and that was about it........... |
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