Faxon and Ballistic Advantage are already producing barrels, with more manufacturers sure to follow. 6mm ARC SR 6mm BR (Bench Rest) SR 6mm Lee Navy BLR 6mm PPC SR 6mm Remington LR 6mm TCU SR 6mm-06 Springfield LR 6mm-284 Winchester LR 6/6.5mm Creedmo or SR / LR 6x62mm Freres LR . 6mm ARC 86287 50 6mm Remington 8622 50 6mm Creedmoor 86280 50 6mm Creedmoor 86280B 2000 25-35 Winchester 86101 50 250 Savage 86105 50 25-06 Remington . Flat trajectory minimized wind drift, high sectional density to aid penetration, tame recoil allowing spotting your own shots and the potential for exceptional accuracy are all part of the ARC package. They shouldve just left it at A.R.C. No idea honestly. Moving load to a Speer 100 Grain Spire-point. Check out the new for 2022 Walther Pro SD with James Tarr and Jens Krogh. EkD>7#q4(BBFh47Nh1nF+ZB4. Bullets used to test the CMMG AR-15 included (left to right) the 108-grain Berger Elite Hunter, 110-Hornady A-Tip Match and the 115-grain Nosler RDF. We recommend the WSR primer, or small rifle primers. Check out our current selection of 6mm GT Rifle Brass below! It could easily be argued the ARC is yet another version of the 6mm PPC (which was never SAMMI standardized) actually a pretty fair assessment, though the fast rifling twist changes everything. The case volume will easily allow for up to 30 grains of powder, but please wait for qualified load data to be available. You will have to trim a bunch. What Federal primers can I use for 6mm ARC? All Rights Reserved Theme by Grace Themes, A Review of American Buffalo by Steven Rinella, Water Filtration Additive Better than Iodine. Bergers 109-gain Long Range Hybrid Target bullet produced the tightest groups of the bolt-rifle test .26- and .13-inch groups using 25.5 and 26.5 grains of IMR-8280 XBR. Another example would be a 16" 5.56 with a midlength gas as being sort . 6mm ARC: Match Federal small pistol and small pistol magnums at your discretion and at your own risk, but they fit and some have reported success. Look at your specific load data and see if what it specifies. Well, regardless of how commercially accepted this new entry becomes, if one were to acquire a rifle or build one of their own, reloading your own 6mm ARC ammo will guarantee it remains in your collection. In theory, magnum primers are more efficient and require slightly less powder to get the same velocities and power. Depending on how you look at it, Hornadys new 6mm ARC is either a necked-down 6.5 Grendel, or yet another version of the 6mm PPC. As with all reloading, if you decide to try this proceed with caution. The action is an MPA/Curtis with a 60-degree bolt throw and fluted, Nitrided bolt body. Handloaders can choose from a multitude of 6mm bullets for applications from varmint and deer hunting to match shooting. There are older veterans, like the SST and Interlock designs up. Brandon explains how his company has streamlined the suppressor buying process. Power Pro Varmint excelled once more, with 26.5 grains resulting in a .37-inch group, 27.5 grains a .54-inch group and 28.5 grains a .46-inch group at 2,678, 2,786 and 2,817 fps, respectively. The rifle includes a built-in inclinometer (bubble level), a RAT Rail accepting bipods and other accessories and a V4 spigot mount and thermal-image optic bridge. The loads I posted above were in a AR. Except for Reloder 15, Precision Rifle and Varget, all are fine-grained or spherical powders that flow like water. Top velocities with 108- and 110-grian bullets reached 2,575 fps. The 6mm ARC shoots far and fast for its size, and can stay supersonic at or beyond 1,200 yards. Anyone have any velocity data with a 14.5"? David Fortier gets a chance to shoot the HK MP7 PDW at drivetanks.com. Buuut it is so stinking dirty suppressed. It also produced a good number of tight groups from this rifle. Preview: Hornady 6mm ARC | An Official Journal Of The NRA The 6mm ARC is an AR-15 platform cartridge that performs well whether it's a close-quarters situation or if there's a need for a longer-range shot to be taken. Now, take the 6.5 Grendel case, neck it to 6mm, give firearms fast rifling to handle long-for-caliber bullets weighing from 103 to 115 grains, including ballistic coefficients (BC) equaling those 6.5 projectiles, and you have Hornadys spanking-new 6mm Advanced Rifle Cartridge, or ARC. [citation needed]. 4 and 5 wandering .25 inch but printing a single hole. You may not reproduce original text or photos without advanced permission in writing. There are older veterans, like the SST and Interlock designs up. Masterpiece Arms (MPA) Matrix Chassis bolt rifle allows custom fitting to any shooter via six grip options, three thumb shelves, five trigger supports, a Matrix buttstock with rear bag butthook, a thumbwheel-adjustable length of pull and comb height and adjustable recoil-plate cant. As for the selection, the burn rate chart has a listing of 22 powder options, but not all are good for semi-automatic rifles. The cartridge was quickly accepted as a Sporting Arms and Ammunition Manufacturers Institute (SAAMI) standard, an excellent start to such a new cartridge. I asked my personal gun smith, who also taught me to reload his opinion on small rifle vs small rifle magnum and this is what he said about it: Ive tried both. Patrick Sweeney shows us his PCC Competition SIG Sauer MPX. Warfare unit, this cartridge has lots of potential as a commercial offering as well. As the story goes, Hornady developed the 6mm ARC under direction from the U.S. Department of Defense, optimizing the Grendel case to meet prescribed goals. 6 mm ARC (Advanced Rifle Cartridge) Lee - 12 Lee - 12 . 6mm Creedmoor Large Rifle vs Small Rifle Primers?? - Sniper's Hide Forum Hornadys initial gas gun data included only 108-grain ELD Match and 110-grain A-Tip Match bullets; lighter bullets from 58 to 105 grains were added within a couple months. Commercial 6mm ARC loads feature bullets selected to deliver ideal performance for hunting, match shooting, and personal protection applications. The rifle weighed 11 pounds, 7 ounces after the addition of a Burris RT-15 3-15x 50mm FFP 30mm scope held in Burris AR-P.E.P.R. 6mm ARC Load Data | Sniper's Hide Forum These sets will not only have the required full-length sizing die to maintain proper case length, but will also completely size the body. Yet, the 6mm ARC was designed to play in the deeper end of the bullet pool. Equally at home in AR-15 platforms and short or micro action bolt guns and suitable for applications from personal defense to match shooting and hunting. document.write(new Date().getFullYear()) Copyright Hornady, Privacy Policy | CCPA Request | Accessibility Policy | Terms of Use, Designed and developed by IdeaBank Marketing. I just loaded up another ladder to 28.4, but sounds like I should go back in the garage and add some more up to. Things started well with 28.5 grains of Accurate A-2520, with a .48-inch group at 2,745 fps. Ensure you have the correct decapping pin when resizing and decapping, as there is no standard and manufacturers can use any size they want. Cartridge Cases - Hornady Manufacturing, Inc MFG #: 13519. ga.src = ('https:' == document.location.protocol ? : 2.085"G1 B.C. The ScenarL have a longer shape over the regular Scenar, for better exterior ballistics. Should be interesting. [7] What the 6mm ARC does offer though is almost comparable velocities and ballistic performance, but out of a compact cartridge that has lessened perceived recoil and fits into the standard AR-15 length actions. Im using RCBS SB/TC dies and just lubing and running. The 6mm ARC offers a 30 to 35% lighter-weight package (gun and ammo). This article looks at theory and our experience, and should not be considered recommendations about primers for the 6mm ARC. Lapuas 105-grain Scenar-L has proven exceptionally accurate in several other 6mm cartridge tests. 0 The powder savings is only a couple tenths of a grain, but that can add up. I ran the Hornady 108gr ELD through the Berger bullet stability calculator after looking at targets fired by various people with 7.5 and 7.7 twist barrels. By the numbers, the 6mm ARC case head measures 0.440, just 0.005 smaller than a 7.6339 case. Hornady is an obvious first choice for selecting 6mm projectiles to load the 6mm ARC with. I wonder if this will make inroads in benchrest, when better brass is vailable? Sort By: Items Per Page: Item Total: (18) 0 - 18 Decapping Pin Large (6 Count) 005-060008 | Hornady $10.63 In Stock Decapping Pin Small (6 Count) 005-060009 | Hornady $10.63 In Stock The neck was set back, allowing more room for long-for-caliber 6mm projectiles in standard AR magazines. Precision Reloading Guide Part 2: Case Preparation Hornady launched the 6mm ARC with three factory loads: a 103-grain ELD-X Precision Hunter at an advertised 2,800 fps, 105-grain BTHP Hornady Black at an advertised 2,750 fps and the 108-grain ELD-Match load at a stated 2,750 fps. Yeah, I saw that post. The maximum cartridge overall length of 2.26 (57.4mm) is identical to the max COAL of .223 Remington which means 6mm ARC is designed to be an AR cartridge. 3 shots touching and a couple wild ones. my memory could be a little off)with a Lever load and a Varget load. 6mm ARC 86287 50 6mm Remington 8622 50 6mm Creedmoor 86280 50 6mm Creedmoor 86280B 2000 25-35 Winchester 86101 50 250 Savage 86105 50 25-06 Remington . Out of stock. Yes, the 6mm ARC cartridge is made to take a small rifle primer. Reloading Reference Tables | RCBS The heavy, hand-lapped barrel is a MPA 416R stainless steel number measuring 26 inches with a 1:7 twist, 58-24 muzzle threads and black CERAKOTE finish. David Fortier is with Paul Pluff of Ruger at 2022 Roundtable checking out Ruger's SFAR - Small Frame AR. (Speer 75 grain HP on top of 25 grains of IMR 4895. Figured I'd start a thread for the 6mm ARC. It can reach maximum results with what is already out there, and these components have been thoroughly tested in other cartridges. That's one great thing about the Hornady 6mm ARC, its not trying to remake the wheel. Some reloading manuals, like the Lee and Nosler handbooks, list regular small rifle primers in their load data, while others recommend either small rifle magnums, or the #41, which is a harder magnum small rifle primer with a thicker cup. 6mm ARC: Cartridge Design 2847 0 obj <>/Filter/FlateDecode/ID[<17398BDBD67F214CBB3755FAA4BE7340><20967B39C4AB1349BB25AF309099C3A9>]/Index[2829 26]/Info 2828 0 R/Length 94/Prev 197341/Root 2830 0 R/Size 2855/Type/XRef/W[1 3 1]>>stream My reformed cases were 1.512 and I modified a lee 6mm PPC case gauge and trimmer to trim to 1.480. Accuracy only improved with IMR-8280 XBR, with 25.5 grains producing a .26-inch group at 2,609 fps, which was quickly overshadowed by a true one-hole .13-inch (center to center) group at 2,678 fps the rifles best group. Already adopted by one Army Spec. 20" barrel with rifle length gas. Power Pro 2000-MR, which also performed well in the AR, proved exceptional with this bullet: 30, 31 and 32 grains producing .44-, .53- and .33-inch groups at 2,754, 2,786 and 2,940 fps, respectively. Hodgdon has perhaps the best variety, including H335, Varget, CFE 223, BL C(2), H4895, and their IMR 4895. 6mm ARC The newest 6mm factory round is the recently announced 6mm ARC (Advanced Rifle Cartridge). David Fortier gets a look at Roundtable with Nathan Robinson. 6mm ARC: 6.5 Creedmoor of the Gas Gun World Both our 6GT and 6mm ARC have 1:7.5" twist barrels. A 31-grain maximum charge of LVR produced a .35-inch group at 2,925 fps. More brass and ammo should arrive soon. 6mm Creedmoor Small Primer question | Sniper's Hide Forum Now I either use #41 primers, or, more frequently, I just load all my .6mm ARC and 6mm ARC brass to .6mm ARC load levels. Why call a cartridge an Arc defined as part of a circle . With this rifle, Hodgdons CFE 223 was the hands down accuracy winner with 28 grains producing a .28-inch group at 2,800 fps, and 29 grains a .52-inch group at 2,835 fps. 6mm ARC vs. 6.5 Grendel Purchased a 6mm Arc upper from Sanders Armory. With the release in 2020, Hornady also launched three factory loads with 103,105 and 108gr (6.7,6.8 and 7.0g) bullet weights and advertised G1 ballistic coefficients of .512, .530 and .536 respectively.[6]. 6mm GT SRP (Small Rifle Primer) $ 130.00 $ 25 Creedmoor SRP (Small Rifle Primer) Out of Stock 118.00 - 6XC SRP (small rifle primer) Out of Stock $ 115.00 - $ 6XC LRP (Large Rifle Primer) Out of Stock 115.00 575.00 Out of Stock Shop All Brass REAMERS Pilot Bushing $ 19.99 Alpha Legacy Reamer $ - $ Shop All Gear A Word From The Alpha Team Extreme caution should be taken when creating loads that go against accepted load data. Sierras 95-grain Tipped MatchKing is a favorite 6mm varmint bullet, with a great BC for weight and improved velocities compared to heavier 6mm bullets with similar profiles. 6mm ARC Everything You Want to Know About It - The Mag Life Shot this group with hornady black 105s today in 5 degrees and howling wind. Ive never loaded any small rifle cartridges, only SAUMs and long action stuff. These would likely be a better fit regarding the cartridges overall length. 6mm ARC Rifles | Wilson Combat Accuracy may also suffer. Then, there will be some neck trimming which needs to be done. These would have the best results if set off with match grade small rifle primers. Hornady is one example of one that has their load data calculated with small rifle magnum primers, namely the Remington 7 1/2 primers. Anyone getting decent velocity with Varget and lighter bullets? Im ordering components and needed to know what to look for. This means you have the option to read your magazine on most popular phones and tablets. 6mm ARC The 6mm Advanced Rifle Cartridge (638mm), or 6mm ARC for short, is a 6 mm (.243) caliber intermediate rifle cartridge introduced by Hornady in 2020, as a low- recoil, high- accuracy long-range cartridge, designed for use in the AR-15 platform at request of a specialized group within the U.S. DoD for its multipurpose combat rifle program. For an ordinary AR-15 rifle chambered for the .223 Rem/5.56mm NATO, a new barrel, magazine and bolt are required to convert to the 6mm ARC. The 6mm ARC cartridge is a new SAAMI-spec cartridge based on the 6.5 Grendel case necked down for 6mm bullets, with the shoulder moved back 0.030. I love the concept and would likely re-chamber my 6mmBR into this for ammo availability. Yes. The Winchester 350 Legend is built with hunters and sport shooters in mind, 350 Legend is versatile on the range and in the deer woods. The shoulder angle was set at 30 degrees. Charges of 28.5, 29.5 and 30.5 grains assembled .48-, .34- and .51-inch groups at 2,602, 2,706 and 2,845 fps, respectively. The Hornady manual states that this second set of data should not be used in gas-guns. 6mm ARC brass forming -& primer flash hole diameter discussion? From the CMMG Endeavor AR, Hornadys A-Tip Match over 25.5 grains of Hodgdon LEVEREVOLUTION produced the best group; .39 inch at 2,263 fps. Essentially, this could mean that you pull the trigger once and it could empty the whole magazine. Finally had the chance to run my 20" proof barrel with factory Hornady ELDX ammo and also some hand loaded 87gr VMAX out to 1000 yards. PDF 6mm ARC (Bolt Gun) - Hornady I will be using once fired Hornady brass to get going. Not crimped. Ill throw my initial pressure testing data into the ring. Powders mirrored those used for AR loads, with the addition of Ramshot TAC, Alliant Power Pro Varmint, Hodgdon Varget, Shooters World Precision Rifle (extrapolated from 6mm Remington BR data) and IMR-8202 XBR. All worked well from the bolt action as well, with Power Pro Varmint, Reloder 15 and IMR-8280 XBR also exceptional performers. This was way over pressure yielding speeds in the 2730 FPS range, heavy ejector swipes and unusably expanded primer pockets. Gas gun data includes 52,000 psi maximum pressures. The 6mm ARC is a better long-range performer. Federal Premiums Gold Medal Match Small Rifle primers were used in all bolt loads. })(); To comment on a post, click Post Title or "Comment" Link. I like the cartridge but the dam name sucks. The free float firing pin makes contact with the next rounds primer when the new round is chambered. The AR-15 platform features a higher magazine capacity. 6mm ARC quick facts: It's a 6mm cartridge similar to 6.5 Grendel, built for the AR-15 platform It's optimized for bullets in the 103 grain - 110 grain range It's got more velocity and less recoil compared to 6.5 Grendel It shares the same parent case with 6.5 Grendel: The 220 Russian So, while others wait to see what ammo options will populate their local gun store, a savvy reloader can be well on his way to making the Hornady 6mm ARC a staple on his reloading bench. Language links are at the top of the page across from the title. If you usually use a regular small rifle primer, we recommend not going straight to a max load after you make the switch. The 6mm ARC as a possible military round doesnt interest me so much as the promise of a serious hunting round. Some Berger bullets require a very fast one turn in 7 inches twist rate. 6mm ARC: Fact or Fiction? Real Performance Results, From-Scratch I was holding on the left side of the marker dot at 100 yards. It seems as though the common choices are: 18" barrel with rifle length gas. It took 4 months to come in. As one last little bit of information before the door is closed on the subject, it would be best to invest in a small-base reloading die set. 6mm ARC - Practical Reloading | Page 4 | Shooters' Forum All barrels will be rifled with a 1-7.5 twist. Yes it is designed to run in AR15-platform rifles. What Do I Need To Shoot the 6mm ARC? Official SAAMI Cartridge (not wildcat) Well shit, you guys and yesterdays target helped convince me: Yeah, his hazmat charges fluctuate, but $230 for 8lbs is about that much cheaper than the next best I could find, so it works out I figured. That, and the longer tube, resulted in average 300-fps velocity gains. You will likely run into feeding problems with an AR-15, due to the shorter overall length, if you try loading bullets lighter than 90 grains. The 6mm ARC uses commonly available 6.5 Grendel magazines/bolts. Just got a 20" proof stainless barrel and I have been very happy with it it. 3dR=j|J{~$'Hk yR_;q $1,449.00. Sierras 95-grain Tipped MatchKing seated over 32 grains of Power Pro 2000-MR produced this .33-inch group from the MPA bolt rifle. With the 110-grain Hornady A-Tip, highlights included a .90-inch group with 28 grains of CFE 223 at 2,481 fps; .39 inch (the smallest group with all AR loads) with 25.5 grains of LVR at 2,262 fps; .97 inch with 26 grains of A-2520 at 2,368 fps and .81 inch with 25.5 grains of Alliant Reloder 15 at 2,383 fps. Those 95s moving fast keep up with 108g ELD with drift and a good bit less drop if you assume a decent starting velocity. CONTACT US All Rights Reserved Wilson Combat. Its a good bet that those companies already loading 6.5mm Grendel will be the quickest onto store shelves. The 6mm ARC cartridge is a new SAAMI-spec cartridge based on the 6.5 Grendel case necked down for 6mm bullets, with the shoulder moved back 0.030. Access features of the Reloading Handbook on your mobile device with the Reloading App. Pet Loads and Handloader are registered trademarks of Wolfe Publishing Company. Less felt recoil than larger short-action-based (308 Win family) cartridges. Here Are 5 Reasons To Consider One! All the hardware you need is currently available at Brownells. The case length of 1.49 results in a lot of bullet space (.77 or 3.16 calibers) which will allow loading projectiles with very long ogives and great external ballistic performance. Theyre also made from the same material and use the same explosive. Fits Short/Mini action bolt rifles The 6mm ARC is a cartridge designed to be a much faster and harder hitting round than the 5.56, but still capable of being shot from the AR-15 platform. Give a Gift The Answer: 6mm Advanced Rifle Cartridge. I hope its stable in my gun. There is room to produce inexpensive range fodder, and create some home brewed match winners. Recently Hornady made big news in what seems to be a proverbial drought of new products with the new 6mm Advanced Rifle Cartridge. The 6mm ARC uses commonly available 6.5 Grendel magazines/bolts. I think it may need cleaned. As of press time, Hornady remained the primary source for properly headstamped brass. Jay Langston, Ballistic Magazine Read More, "The 6mm ARC is unique among rifle cartridges in that it fits in an AR-15-pattern action, functions reliably out of standard-capacity 24- or 17-round magazines, and remains supersonic beyond 1,000 yards in a standard atmosphere." (4) not available. This versatile cartridge does much of what larger cartridges can and everything that smaller cartridges can't. The handloads chambered especially tight in this rifles match chamber; the bolt turned down with some small effort, but otherwise it shot well. hb```,? This rifle assembled five-shot, 100-yard groups I would deem better than average for any AR-15. PRIMER LEGEND . We also read a report that said for one manufacturer, theyre identical to the regular small rifle primers. I doubt it will take long before virgin brass from Hornady becomes available. The chassis rifle proved so accurate (.64-inch overall average from 45 loads) that only combinations printing near or less than .50 inch with five shots at 100 yards are worth mentioning. If you have light firing pin strikes, you may have problems with these, as they have a harder cup, but the 6mm ARC was originally designed to shoot this harder nato style primer. brass weight? Even with a flat-shooting 6mm target bullet, a difference of 30 fps in muzzle velocity can translate to 7 inches of vertical at 1,000 yards, turning what might have been a good hit into a clean miss. It is going to be interesting to see bolt life. So your cabinet may already be full with some, or all of these options. I have used #400s and Br4s but now I am mostly using #41s. Not a fan of that watch button in the upper right of threads? Most reloaders are able to use these interchangeably with the magnum small rifle primers without adjusting their load data, but you do your own testing if you choose to use the #41 small rifle primers in your 6mm ARC loads. The accuracy of the ARC is superb." The groups showed signs, at least to me, of not being adequately stabilized which is why I went to the calculator. This was done to help prevent 6.5 Grendel from chambering in 6mm ARC rifles. 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; Alliant's Reloader 15 would be another good option to consider. Conceivably, this means. This 6mm ARC reloading data is intended for use in gas guns (e.g. Some may want to try and reform 6.5mm Grendel cases into 6mm ARC. I suggest considering CCI BR-4s. For example, the data in the Hornady 11th Edition Manual for an 18 in (457 mm)-barrelled AR-15 platform firearm was on average 200-300 ft/s (60-90 m/s) less than the data for the 24 in (610 mm)-barrelled CZ 527 bolt action rifle. Wolfe Publishing Company | 2180 Gulfstream Suite A | Prescott, AZ 86301. SFX9 HC 3.25 Solid Frame X-TAC 15 Round, SFX9 HC 3.25 Solid Frame X-TAC 10 Round. var _gaq = _gaq || []; Yes, some reloading data are made with small rifle magnum primers. The 109-grain Berger Long Range Hybrid Target would be the ticket for shooters addressing distant targets. They will expand on small varmints at 6mm Creedmoor velocities, so they should work well on average-sized hogs or smaller deer. Half of these are designed for hunting and the rest for match shooting. The 6mm ARC is a serious cartridge, particularly from an AR-15, and one I hope fares well in the fickle world of cartridge popularity. Shooter can self-spot impacts on or off target to make rapid adjustments. 6mm ARC Unprimed Cases (50 ct) Item No 86287, 6mm ARC Series III Two-Die Rifle Die Set (.243) Item No 546251, 6mm ARC Full Length Die (.243) Item No 046262, 6mm ARC Seating Die (.243) Item No 044244, Small Rifle Case Feeder Plate Item No 095314, Bullet Puller Collet #3 (.243) Item No 392156. 6mm Lee Navy .243 BLR 6mm PPC .243 SR 6mm Remington .243 LR 6mm TCU .243 SR 6mm-06 Springfield .243 LR 6mm-284 Winchester .243 LR I would recommend getting a Body Die to help correctly set the new shoulder, as the 6mm ARCs is slightly further back. Maximum pressures in the turn bolt were established at 62,000 psi. I plan on doing a build when parts come available. var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); Initially tested and fielded by US Special Operations forces, the 6mm ARC utilizes efficient, high-BC bullets to deliver unprecedented long-range performance with a wide variety of available bullets. Some recommend an AR specific primer, with a thicker cup, but we havent ever had any issue with using regular small rifle primers in a 6mm ARC. Because of this, we recommend that you subscribe to our bimonthly newsletter to keep prepping, emergency preparedness, and self reliance on your mind. From a military standpoint, Hornady's 6mm ARC is designed as an improvement over both the 5.56 NATO and the 7.62 NATO rounds traditionally employed in the U.S. arsenal. So, I suggest staying loading bullets 90 grains and heavier. Accurate A-2520 produced a .43-inch group at 2,886 fps, while Power Pro 2000-MR shined again. SIGHTRON S6 5-30x56 ED Line of Premium Riflescopes: New for 2022, B&T USA 16-inch SPC9 Carbine: New for 2022. From Ramshot Powders you should consider X-Terminator and TAC. Subscriber Services. 6mm ARC | Review of the Hornady Cartridge for the AR-15 Platform [9] The 6mm ARC utilizes the same bolt head size as the 6.5mm Grendel, and 6.5mm Grendel-compatible AR-pattern box magazines have also been used successfully with the 6mm ARC. JavaScript is disabled. Tested, selected and fielded by a specialized group within the U.S. DoD for its multipurpose combat rifle program, the versatile 6mm ARC does much of what larger cartridges can and everything that smaller cartridges cant. Like Greg talks about in the 1st of his video. If you are interested in a detailed history of the 6mm ARC, Senior Field Editor David Fortier provided a great rundown in this article. What kind of dies are you using?