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Current status on 6 ARC reliability?
- Thread starter Bakwa
- Start date
SgtofArms.com is your huckleberry.
I know guys running their 6 ARCs HARD with no issues.
I know guys running their 6 ARCs HARD with no issues.
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Really I want to know what mags they are using for the KS-6 (its a KS-1 lower) so I can use them in my 6ARC.
Not my video but some footage from one of the SPR classes Rudy was talking about. Seems like a good bit of shooting.
That video was worth watching. I like the use of Selma’s containers.
If you use G7 drag model since you’re going past 600yds with a Spitzer bullet, you’re looking at 775yds supersonic reach with a 115gr Nosler CC, assuming a .190 G7 (there’s a token boat tail on the 115gr CC, so its BC might be lower than stated). G1 will give you a good idea of what it will do out to 600yds, but then will be really optimistic after that with false drop, drift, velocity, and energy values. That bullet, like most .224” bullets, have a little parachute they deploy as soon as they exit the muzzle, it seems.
Here’s the 115gr Nosler at 2600fps, assuming a .190 G7 BC, 2.7” scope height, sea level:
300yds 1952fps 973ft-lbs 1.3 Mils drop 0.9 mils drift
775yds 1128fps 325ft-lbs 8.5 mils drop 3 mils drift
One of the first clues you will see with any of the bullet weights for 6.8 SPC is there isn’t any doppler radar data for any of them, because it’s a waste of time really. You really want to be in the mid-high .4s for G1, or .230s and higher for G7. That’s why I look at the Berger .277” 130gr Hunter and VLD, which would basically turn a 6.8 SPC into a Grendel shooting 120gr BCs. You would want a tighter twist rate for the 130gr Bergers, preferably in the 1/9” region. Use PRI mags and load long.
With the 130gr .277”/6.8 Classic Hunter, the G7 is .251, which is nice.
300yds 1922fps 1067ft-lbs 1.5 mils drop 0.7 mils drift
900yds 1135fps 372ft-lbs 11.1 Mils drop 2.8 mils drift
That’s a pretty solid DMR load right there. The Classic Hunter is more aerodynamic than the .277”/6.8 130gr VLD, which is counter-intuitive in how they have them named. Accurate Powders has data for that from a 20” using LT-30, but it’s interesting because they have one load with 2.260” COL, and another with 2.350” (not AR-15 magazine compatible). I would use PRI mags and load to 2.300” if they will clear reliably when stacked.
Sorry. From a 16.3” AK or AR-15 in 7.62x39, with a 123gr flat-based short bus bullet, you’re supersonic out to 475yds.
I stuff the carrier raceway with foam during spraying and allow Cerakote to build up inside the barrel extension tunnel. I also tape off the mag catch slot or sand it down if I did a really matte texture coat. I just have others do it now. Got tired of FDE nose even wearing respirators and plenty ventilated. I prefer dusted anodizing with the sand blast tank, not removed anodizing, then Cerakote. Anodizing is like surface-hardening for aluminum and should not be messed with aggressively to get down to the aluminum, especially on all these cheap receiver sets with minimal anodizing that don’t meet the Mil-Std for anodizing thickness.
You see it in guns that start out really tightly-fit, then turn into rattle traps after a few trips to the range. The more you shoot, the more you see the validity of the TDP.
Still not saying it's a dmr round, not picking that fight. I know you're a grendel guy (I think everyone knows). I appreciate your input on military history and have enjoyed reading many of your posts.
Anyhow, you can get 2.3 reliably from ASC mags as well. 2.35 is achievable with a windowed mag (obviously this is not just the 6.8). Some people have pushed it pretty hard. The pressure limit is 58k and the bolts are stronger. It's much more than what Rem screwed up and is a great hunting round.
I have personally migrated to E-lander 17 round magazines for my rifles. I use them in PRS and for hunting, so I don't have much need for 25 rounders. I have some 25 rounders and they work well until they get sooty, then it seems the bolt out-runs the magazine. I also have some 10-round ASC's for big game (where legal). I've found the E-landers to be pretty solid in general.
This was my experience with the 24rd E-Lander mags with 6.5G. They'd work great for a few trips with an 18" suppressed Larue UU or 12" suppressed PSA upper, but a little bit of blowback crud and they'd turn into failure to feed machines.
I eventually gave my decade old 28rd 7.62x39 CPD mags a go and they're great. Not sure what the secret sauce is with those mags, but they just run....even though they're probably the nastiest mags I own due to running them with a suppressed 7" 7.62x39 upper on my M16 lower when steel cased x39 was dirt cheap
Anyone have any insight on the longevity of brass when using 6 ARC in a gas gun? I just heard from a friend that the AMU doesn’t even reload their ARC, they just toss it (
) because it’s only good for two’ish reloads before the cases are trash.
I have no way to validate this but have to believe someone has.
) because it’s only good for two’ish reloads before the cases are trash. I have no way to validate this but have to believe someone has.
Haven’t worn any out yet but it does take a beating. I’m on two firings so far I thinkAnyone have any insight on the longevity of brass when using 6 ARC in a gas gun? I just heard from a friend that the AMU doesn’t even reload their ARC, they just toss it (
I have no way to validate this but have to believe someone has.
Anyone have any insight on the longevity of brass when using 6 ARC in a gas gun? I just heard from a friend that the AMU doesn’t even reload their ARC, they just toss it (
I have no way to validate this but have to believe someone has.
Not sure why a 6mm neck would cause the cases to all of a sudden give up the ghost in two firings. I'm on my third firing with Hornady 6.5G brass (first as factory ammo and two trips through my press) and others have claimed 10+ reloading cycles out of their Hornady brass. I presume Lapua or the like would last even longer. 6ARC is running at the same (lowish) pressure as 6.5G to save the bolts, no? Maybe AMU is hotrodding it?
I haven't really been keeping count, but I've got to be on the 4th or 5th firing on some of mine. I just go/no go the primer pocket when decapping, and toss cases once the no go fits. I've lost some, but I don't really think at a higher rate than my Grendel, and probably a lower rate than my SFAR.
Whats everyone running for buffers and springs in the 6ARC? I'm putting one together with an 18" Proof rifle +1 gas that will get an SLR ADG and will be ran suppressed. Will be using a standard carbine buffer tube. I've got standard LMT buffers and springs, LMT H1's, and Geissele H1's, H2's, and H3's.
I’m using adjustable gas with a standard H1 and carbine spring. I think if you can adjust the gas, you’d want the lightest weight buffer cycling back and forth.
I know some of the guys shooting PRS are running regular USGI shit in theirs with an AGB.
If it was me, it would be a LMOS carrier + SCS to soften the recoil impulse.
A 15 lb 6 ARC still has a violent recoil impulse, being able to tame that should result in much faster follow up shots.
If it was me, it would be a LMOS carrier + SCS to soften the recoil impulse.
A 15 lb 6 ARC still has a violent recoil impulse, being able to tame that should result in much faster follow up shots.
I have an 18” Proof +1 with a Superlative Arms gas block & a full-auto weight carrier. It’s been shot almost exclusively suppressed on lowers with both a standard rifle buffer and a VLTOR A5 system (A5H2 5.3 oz standard weight buffer). The upper has been easy to tune on both lowers, using both factory ammo and hand loads loaded within Hornady’s suggested load data using Lever.
It’s pretty soft shooting, but obviously still moves more than the 223 I have set up the same way.
And the ARC is hella dirty suppressed.
Well that's not encouraging. Is it dirtier than IMI or similar through a suppressed 5.56? How many rounds can you go without wearing blackface?
Once the gun was tuned properly I haven't had much of an issue with gas to the face. By dirty I mean that brass comes out of the gun covered in soot, and it works its way down into the mags, so I've taken to cleaning them occasionally (something I don't really do with a 5.56). The fouling on fired brass is definitely worse than with anything I have in 5.56, or really any other caliber I own.
Basically the same as others have said earlier in the thread, the cartridge, at least in Hornady factory loadings and reloaded with Lever, seems unusually dirty. The action generally fouls much more quickly than a 5.56, and normal suppressor related fouling is also amplified.
It's still been a lot of fun to shoot.
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I don't mind dirty brass or mags, I usually have that with my 556's anyway since my 223 can has a lot of back pressure (AAC Ranger 2). My Ultra 7 which I'd run on an ARC has had a lot less back pressure in comparison on the same guns. Gas to the face however is a lot bigger issue to me. This will be a low volume rifle though. It will be mostly used for hunting and a few range trips per year with probably no more than 100 rounds each time. I have two 223 wylde DMR rifles I can take to the range if I want to shoot a lot or if I get the itch to do a DMR match. I hate cleaning as much as the next person but if they're reliable for 400 rounds between cleanings like many are suggesting then that's a year or better of shooting for me. I'm also not opposed to just scrapping the project and sticking with a bolt gun either.
What suppressor are you running?
My 6.5G brass, even with an AGB, was coming out filthy when running my SDN-6 on both an 18" Larue and PSA 12" upper.
For your Ranger 2 backpressure woes, check this thread out: AAC Resto Mod
I have not run the SDN-6 to Ranger 7 converted can on my 6.5G ARs yet, but the difference on my 10.3" 6945 this past weekend was noticeable, and I suspect it will also be noticeable on the 6.5G guns.
I’ve seen that but mine is already converted by ECCO and after the fuckery of sending this thing back to AAC 4 times for factory defects I won’t give them another dime of my money. With the ECCO modification using a Plan B and Rearden brake it’s down to an acceptable level.
I tried running JP's Captured buffer but it was too light causing feeding issues due to the speed of the buffer cycling faster than the next round moving up in the mag. Swapped to H1 buffer and milspec spring and it worked fine but didn't like the twang of the spring so I swapped it out for an Armaspec H1 Stealth buffer for the last 800rds or so and zero issues.
-20" proof
-Superlative gas block
-CMC Enhanced 6 ARC bcg
It was an option just not the best choice financially because I had several milspec buffers of various weights and springs and the Armaspec Stealth buffer in the spare parts bin. ;-) And I'm not going to drop $42+ shipping for 1 tungsten buffer.
One of my shooting buddies is up to 8 reloads on his Hornady brass shooting out of a 16" Larue UU upper kit. He admittedly loads them pretty soft though. I can get load details if you want.
I have a Proof carbon 18" Rifle+1 as well. Non adjustable GB and Area 419 Hellfire brake. On a standard TDP lower with carbine RE. I've tried it with Tubb spring and H1 and also a JP SCS with 1 tungsten and 2 steel. Both run very nicely (can't really tell the difference TBH) with positive and consistent ejection to the 4:00. I can reliably spot hits out to 800+ if I'm shooting from a bipod and rear bag. Improvised support positions are a little harder of course.
Just as a data point, I'm about 100 rounds in (all Hornady factory 108 ELDM) using Duramag 10 and 20 round mags with zero malfunctions. The first ~20 shots had ejector swipes on the brass but that seems to have self rectified. Obviously lots more testing to do, but I'm extremely pleased overall. I have shot it out to 1000 yards including a 3 round 0.3 MOA group which is exceptional, but not representative. Typical accuracy is around 1.25 MOA at that distance for 5 rounds groups. Dispersion seems to be much tighter at closer distances including repeatable 0.6 MOA 5 round groups at 600.
I am running rifle length tube and Super 42 spring standard rifle buffer. SA adjustable gas block, rifle gas system and 22" X-Caliber barrel. Running well for me.
Thanks for the feedback everyone. I’ll drop a super 42 H1 in to start out and go from there.
I'm running a SprinCo red spring and H1 buffer in my 6.5G. I've gone well beyond 1k rounds between cleanings and I have not had reliability issues.
Saw this when it was put out and automatically got ticked off lol. After I waited got a custom ARC barrel and now have a bunch of brass. Now this! Grrrrrr!! Seems pretty legit and can run faster and higher pressure and makes sense with the casing! We shall see if I build one of these too!
We were. 7.62x51 vs 7.62x54 from elevated positions, not to mention DShK. Its why the TOW and Mortars were so vital, the only organic weapon system that could reach them.
300NM machine guns are the future for this reason. But man is that going to suck to carry that ammo.
This thing?
DShK - Wikipedia
Jeez. That decidedly does not look like something I want firing at me.
Yea its the soviet block version of the M2 50cal. Not fun at all, especially when little midgets in PJ's are willing to hump one up a mountain at 10k feet and a bunch of ammo to ruin your party.This thing?
DShK - Wikipedia
en.m.wikipedia.org
Jeez. That decidedly does not look like something I want firing at me.
I’d definitely appreciate the load data. I have some friends at Geissele that are loading for it and are saying the brass is lasting.
It seems the more industry people I talk to that the ARC has a negative reputation that is starting to wane depending on who you hit.
Yes - load data and specifics much appreciated!
Seems the heaviest factory load will be a 90gr ELD-X, but I wonder what kind of velocity you could get with a 105-108gr 6mm in it.
ETA: They have load data for a 100gr bullet, but the question still stands. I'm guessing we'll have some real-world info by Dec/Jan if their 1 Nov launch date holds. I also wonder if you can push this round closer to 5.56 60k+ pressures due to not relying on the larger Grendel bolt face and the associated limitations that brings.
I haven't seen a chamber drawing yet but just looking at it I'm guessing those bullets just won't fit.
Honestly that just doesn't look compelling to me at all, it's not much faster than the ARC with 90gr bullets, and doesn't look like it can handle the heavier weights very well. I haven't actually had any feeding, gas tuning or bolt problems with my ARCs, maybe it would make sense if you had, but it seems that most folks who actually shoot ARC are pretty pleased and this thing looks a lot like a step in the wrong direction.
That's the conundrum of 6/6.5mm AR15 cartridges. Case capacity or shoulder location for heavies. You have to pick and you can't have both.
Yes! True that! It is definitely a give and take with every so called new hotness. That's why i waited as long as I did before committing to ARC!
No I haven't had any problems with mine at all. Was just forming some kind of quick opinion on the short video. Wasn't aware it probably wasn't able to take the heavier projectiles which I shoot. And seemed like you may be able to stand on it a bit harder. Good thing I don't jump or chase the Caliber hots for the time. Hell I am still stuck on my Grendles! I Love shooting and hunting with them. ARC was an easy cross over for me!
I was pretty hot for 6ARC until I saw the big shoulder move. 6AR works pretty well with 95gr projectiles. The reality is that 6.5G and 6ARC have some limitations. It's true that you can connect up at 700 yards with either but they are arguably not the right tool for longer ranges. When you start reducing the distance you don't need the heaviest of heavies. I'm still loading 107TMK in 6.5G and they're excellent. Powder choices are wider and I can run them with less pressure. The same is true for 6AR with 95gr VLD or ELDM.
Perhaps I'm all alone on this but I'd rather step up to a 6GT AR308 with 105gr to 115gr Projectiles. The intermediate cartridge compliments low mass BCGS, the weight is still close to an AR15, and optics mount easier. Most of the 6ARC builds I'm seeing are long heavy barrels that will never get carried anyways. Hornady makes brass for all three if that matters.
