Hands-On: NEW CMMG Endeavor 6mm ARC AR-15

I just got an 18” Shaw stainless spiral fluted match barrel. I’ve gotten everything but a bcg. No brass no bullets but I’m sure they’ll be along. Found A set of dies and grabbed them up. I have great expectations for this build. Thank You for the data and Thank You Hornady. Let’s do this!

I bought a 20" xcaliber 1×7.7 twist ar barrel. Built yhe upper myself with a gibbs side charger. This is the most accurate AR I own. I tried a bunch of different loads. 4064 works really nice in my rifle. I get about 2750 fps with 105 rdf bullets, and cci primers. I can load it up and get 2850, but I see some pressure signs there so I backed it off. This combination is a .5 moa combo if I'm on. But this barrel is very accurate with factory ammo. I just got some factory 108 eld's and it shot better than my reloads. Fwiw.

As i have been looking at ammo day to day i had noticed on the bare shelves at my local shop there is consitantly 6mm arc. After weeks of seeing this i thought to myself… i am having a difficult time finding the ammo i am wanting, maybe i should look at this 6mm arc and see what its all about because its available… come to find out. everything on paper says to me this round is going to be fantastic. I've started buying lots of it and am looking forward to build the perfect rifle for it.:)

Several weeks ago, in my quest for the elusive 6.5G ammo, I came across a shop well stocked with ARC. I went to the van and watched a video. I walked back in and bought 300 rounds.
I have 6.5G in 12", 16" & 24" for AR, and a 26.5 CZ bolt gun. Now I need a 20" 6mmARC barrel to play with. Kind of infatuated with 6.5G, but an elusive lass leaves opportunities for new discoveries.

I was wondering what combination of buffer and buffer spring did you use? Also, was this a standard gas rifle length tube ? I’m interested in putting one together, but I see barrels with a standard length, a +1 and a + 2 gas tube length. What is your opinion on these barrels? Are they necessary?
Thanks for your time, and great video!

What color is that? I’m looking at getting a cmmg upper.

I ordered the 6ARC resolute upper in Dec, 2020. I should have it by March. I have a large stock of heavy 6MM bullets in the 105-107 weight range. I can't wait to see how it shoots with top quality custom bullets.

Waiting to see how it handles at 1000yards. And have u tried gibbz arms side chargers? Its my knew thing. Seems better than rear charging. Thanks for your video and your time. 🙂

Interested in 6mm arc. What are your thoughts on a 12.5" for the 6mm? Pros/cons……?

Chambering a 7.5 twist brux 24" 6mm arc as we speak.

Thank you, just heard about this round, looking to build one now.

Is the bolt a shaved down 5.56?

Wow you can really see barrel flex in the openings slow motion shots! The suppressor definitely magnified it but still cool.

Purchased the Odin Works 21" barrel for 6MM ARC the other day. Waiting for it to come in also added the Atlas 6 comp to it hoping to balance out barrel harmonics with it. My biggest concern is the magazine like you mentioned. Have you / can you test any magazines with higher capacity? Tons of reports from people stating going past 10 / 15 rounds will fail to feed.

Compare 6 mm arc vs the 224 valkyrie .

Ultimate Predator round in a AR15 platform?

I own a CMMG Banshee in .45 with a Obsidian .45 suppressor, Which I love. Just ordered an Endeavor 20" upper in 6mm ARC. Never was interested in the 6.5, or 6.8 AR calibers, but got excited when this new cartridge with .308 ballistics in an AR-15 platform came out. Hope it works out

I placed an order for a Resolute 100 upper a couple weeks ago, but they’re backordered 10+ weeks 😢

I will be swapping out the barrel on my 5.56 18" SPR with an 18" 6MM ARC SPR barrel. Very impressed with this round.

Hi Gavin great channel and brilliant content. Over the last few years we have seen 3 new 6 mm cartridges and we also have the 243. What is the chance we could see a series based on say 2 target projectiles and 3 or more hunting projectiles and a range of powders to suit. Maybe cover 243, 6 creedmoor, 6 prc and 6 arc with a bolt gun and an AR. To compare and see what the real ballistic difference is. Keep doing what your doing producing fabulous content.

What color is the weapon?

What KRG p/n did you use for the ARCA rail? Didn’t see a MLOK rail on their website.

so theres arc and arca??

Still waiting on my CMMG Endeavor 300 MK4 20in. I Have a lower with a nice crisp 3.5 match trigger just waiting for this upper. Also order a Vortex Strike Eagle 5-25×56 MRAD and Mount. Guess I’ll be waiting a while for that CMMG upper. No matter Can’t find Hornady Ammo Anywhere.

🤮🤮🤮🤮🤮🤮🤮🤮🤮🤮🤮🤮🤮🤮🤮🤮🤮🤮👎👎👎👎👎👎

What do you mean you dont have a magnetospeed mount compatible with your surpressor? Mine works well with any surpressor. The thiccc ones work just with the rubber feet and no spacers.

You just peaked my interest in this round and would like to see how it shoots in a bolt gun. I'm thinking of spinning up a barrel and developing the 6ARC for PRS use. My current 6.5 Creed shoots very well but better recoil characteristics would be desireable. Another great video!

I bought the cmmg 300mk57 upper to go with my ruger 57 as a combo set. I have it setting on a spikes tactical complete punisher lower. Im pretty happy with both,the spikes does very well bit not as well as when i had my upper sitting on my ruger 556 lower. But wish i could afford more cmmg products,my goal is to have a cmmg 9mm & 22LR uppers for my lower to be able to pack thrm all into 1 bkpk for bugout purposes if needed. The main reason i love 5.7×28 round so much is that its a gr8 round with a punch & im able to haul a large quantity of them at 1 time. If i had to bugout in a hurry,id take my cmmg 300mk57 upper setup with my ruger 57 & i could carry 1k rounds with no problems. I carry a lot of faith in the 5.7×28 round,its accurate,powerful enough & can haul a lot compared to 9mm,556,3030 etc. To me its the perfect bugout round.

Will this 6mm arc work in a ruger 556 & will they load into a standard mag for the AR15,i cant seem tofind the answere im looking for online,not very knowledgable about rifles & the ammo differences,im a pretty decent shooter & a very safe handler of my weapons,im just not very skilled at the different tyoes of ammos & all that junk,i buy what is intended for each of my firearms to stay on the safe side,but would like to try out the 6mm arc,but i need to know if they work in a standard AR15 or will i need to buy any accessories to be able to shoot the 6mm arc.

I ordered a bolt and a 20" barrel from CMMG on 6/5/20, and it is still on back order………… I have everything else ready to go, just need the barrel.
What was the average velocity out of the Hornady Black Ammo from that barrel?

I want to see this in a hunting application. I really like the .22-.25 size rounds.

Thanks

Love the gray and black color scheme! My Grendels are FDE and black. Might have to go gray and black for 6mmARC.

I have found the best performance and groups while using 103 eldx’s & burning 8208, outta my 6mmAR.

I’ve been reloading for 6mm ARC with a 20.5 inch total barrel length (brake included) getting upper 2700s in velocity with 26.8 Grains of IMR 8208 XBR and a SD of 8.9, ES of 23 also getting around .45 inch groups

Get West Desert Shooter up there and compare the CMMG to the UPR.

Having great experience with 6ARC. 20" BA barrel. Running 105bthp black ammo. Seeing 2600fps with
.75-1" groups. With handloads using CFE223 getting 2699fps no pressure signs, group size avg .5-.7". Over 200 rounds fired, consistent hits out to 830yds, wind does effect these little 105bthp significantly, good learning opportunity, been spoiled shooting 300winmag and 338L. Going to run another 100+ rounds this weekend on the 600yd range at Asymmetric Solutions.
So far I love it, definatly the most accurate & precise AR15 I ever had.
Using the deflector brake to prevent damage to ejected brass. Annealing cases after 4th firing. Only had to trim. 007" so far.

Hello. I am a new subscriber and new to shooting and reloading. I was in the USMC 35 years ago, but haven't really shot much since then. I am a Mechanical Engineer and have a fair amount of technical training (BS, MS, PhD). On a more humorous note, I have the exact same Precision Matthews Knee-mill and Lathe in my personal shop. I cracked up when I saw them in the background of your videos. In any event, I only provided the previous personal information to try to establish SOME credentials, since I am an obvious novice on these topics 🙂 I do have a genuine question, however, after carefully watching your video (and "The Social Regressive" video on 6mm ARC) – Why not just purchase a 6.5 Creedmor instead of a 6mm ARC? It appears to be flatter shooting, fights the wind better, and retains more energy for more distance than the 6mm ARC. Also, there are numerous and inexpensive bolt action rifles available for 6.5 Creedmoor. Factory ammunition is extremely plentiful and cheap. I also just went to the CMMG website and it has the Endeavor 300 in both calibers. Am I missing something? It doesn't appear that the 6mm ARC is more interchangeable with standard 5.56 equipment (need a new barrel, bolt, and magazine). I am sure that I have just missed a key advantage, but I would appreciate any insight. I am not trolling you; I am genuinely interested and puzzled by the fundamental purpose of the 6mm ARC. Thank you in advance for your time.

Can u purchase this gun

TriggerTech and Mystic Precision… 👍
Two fine Canadian firearms companies, who need all the support they can get – given the recent AR-ban in Canada and the drop in business.

I’ve been watching your show and I’m curious do you do any work with hunting rounds or hunting rifles to get the best out of them like A 270 round I would like to be more confident in a long line shooting or hunting

I'm really digg'n what I"m hearing about the 6mm ARC. I have an extra receiver set waiting for a build project. With that said, I would love to see you do a video on the Gordon's reloading tool.

Good stuff man. Always appreciate your scientific approach.

Brownells has the Wilson 6mm arc dies and guages in stock

I'd love to have a CMMG but I can't afford it right now

try imr 8208 xbr 30 gr

I built my 6 ARC using ZEV upper and lower receivers and a 20" proof research barrel. My only problem is ammo availability I will mostly be using the Hornady Precision Hunter 103gr ammo but just can't find any. Oh well closer to hunt'n season hopefully there will be more.

Sooo a modified 243? At 2x the cost?

Good video! I like the rail choice, buttstock and dropping the Geiselle trigger as they are very overhyped in my humble opinion. Have you tried the Timney Calvin Elite trigger? After shooting many many AR platform triggers I really like the Calvin. Would be interested to see how it compares with your trigger scan. Not so much a fan of fan of the optic/mount choice as I think you could find a superior optic/mount in same price range or for just a bit more money. Also Radian charging handles are the high end standard especially if you ever shoot it suppressed. But then again it is not my rifle and you do what you want brother. Thanks again for the continued excellent content.

I would try some ramshot big game and some n540 these powders work really good on my 224 grendel. So did a compressed load of 6.5 sta ball