New 6mm Advanced Rifle Cartridge
- Thread starter Gtscotty
- Start date
I picked up CATs 6arc can to dedicate to mine and love it. Shot at a local indoor range yesterday with it and had zero gas to the face, and sounded great when Ive shot it outdoors as well. 18” rlgs with a5h2 and springo green spring it shoots very smooth
About to pop my cherry on a 6ARC. I do run and gun shit so absolute accuracy and MV is not as important as a package that shoots about MOA and is handy over 3-8 miles.
Pulling down my 14.5” intermediate gas upper and replacing with a Noveske Afghan 14.5, will have a P&W Surefire three prong and if I run a can it’ll be a 7.62 RC2.
Have some Duramags on the way as well as 4 different bullets, from 95gr to 107.
Leaving brass along a course is gonna suck,,, but I think this may be a little advantage in the DMR style R&Gs without going to the weight and recoil of a large frame. We’ll see..
If I like it, will probably wear a 4-16x42 ATACR eventually. Will start with either the G3 1-10 that’s on it now or I’ll move a 3-15 NXS F1 over, though that gonna be choncky with a red dot up top .
Pulling down my 14.5” intermediate gas upper and replacing with a Noveske Afghan 14.5, will have a P&W Surefire three prong and if I run a can it’ll be a 7.62 RC2.
Have some Duramags on the way as well as 4 different bullets, from 95gr to 107.
Leaving brass along a course is gonna suck,,, but I think this may be a little advantage in the DMR style R&Gs without going to the weight and recoil of a large frame. We’ll see..
If I like it, will probably wear a 4-16x42 ATACR eventually. Will start with either the G3 1-10 that’s on it now or I’ll move a 3-15 NXS F1 over, though that gonna be choncky with a red dot up top .
Noveskes DDF barrel is lighter than the afghan if that’s important to you. I imagine they’ll go on sale again Labor Day.
Yep, I run a CAT Noah Ti on my main 6 ARC and it's pretty great in that application for gas and suppression. My B&T RBS 762 also does well with the little ARC.
Opinions please. Rifle is upside down in pic. Installed this mlok pic rail for the bipod mount. Seems to be minimal clearance between the mlok screw and gas block. With the bipod installed if I push down on the barrel only I can feel it make contact, but without pressure there’s no contact. Is this going to be an issue, or do I need to grind the screw down or move the mount altogether?
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I’d move the mount or get a shorter screw
Looks like you can loosen the mlok screws and slide the pic rail forward a little and then tighten it back down.
Just fyi, I have started running my bipods a little further back on the rail of my gas guns(toward the receiver)and I still get great stability but have noticed slightly less deviation on target than running the bipod all the way out toward the muzzle.
You can use a 7 slot pic rail and completely bridge over the gas block. Its what I ended up doing to make sure no contact.
Finally got the parts painted up with Alumahyde and put together this weekend, and a Rexus Ultra bolt on the way. I will say the BFK upper was a bit too interference fit with my barrel, even freezing the barrel and lightly torching the receiver threads, the rubber mallet had to put in some work to get the barrel in far enough that I could fully seat it with the barrel nut.
How does the 77g fall faster than the 108?
pretty much the same drop to 500yd... 108 has a little better wind, as expected, 108 pulls away in drop slightly past 500 and more so in wind past 500, again as expected.
77smk @ 2750
108 ELD @ 2575
Finally got around to shooting the GFR. TLDR: Gun shoots great, I failed it in preparation and execution lol. I started out standing off a tripod because I haven’t had much time to bushog around here, and groups were moa+. Decided to try prone and things got a lot better until I realized the ammo was sitting in the sun in 96 degree heat and the suppressor had come loose. Shots 15-19 with factory 103 Eldx in the first pic. First shot went way high and that when I found the can issue and the ammo issue. Let things cool down and 16-19 went much better, then 2 more a few minutes later to confirm. The shot on the right in the second pic was shot 1 of the day after bore sighting.
Overall I’m impressed with this thing so far. Need to stretch it out some and get it bloody!
Overall I’m impressed with this thing so far. Need to stretch it out some and get it bloody!
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Mulling over switching my current 20" barreled 6.5 grendel AR-15 to 6mm ARC. From what I gather the brass can be sized down to 6mm ARC? Looking to do a 18-20" barrel threaded for a brake and prefer heavy profile but fluted. Is it worth switching as I currently reload and have all the dies and brass for 6.5 grendel. What barrels are available for the $500-$700? I'll want to buy a matched barrel and bolt. Thanks
Check out Patriot Valley Arms AR barrels. 6 ARC , they will flute it for you and you can get a matched bolt. Not sure about the "HEAVY" profile though.
Craddock RTR. .875 gas journal. Or Bartlein but that would likely exceed your budget have a longer wait. My experience with 3 RTR barrels, 18 and 22” has been excellent. But agree with supercorndog - for what reason?
Here are links to a variety of 6 arc ar barrels
- McGowan Custom 6 ARC 416R Stainless Steel barrel (with muzzle threads and cerakote) (button rifled and hand lapped) ($420)
- Precision Firearms Custom (criterion blank) ($560 with headspaced bolt) (other blanks available for +$390: Krieger, CRB, Muller Works, and Bartlein)
- Noveske 18” SS barrel with gas block, gas tube, & JP headspaced bolt ($540) (gas port on 14.5” is 0.074”
- Blackhole Weaponry 416R Nitrided Custom 6mm AR-15 Barrels (polygonal) (standard profile) ($350)
- Rosco 6mm ARC Purebred (16” or 20”) SPR barrel ($250)
- Craddock RTR 6 ARC 16” Intermediate w/ muzzle threads (+$60 for headspaced bolt) ($350)
- X-Caliber Custom AR Barrel 6 ARC 18” (add Rubber City headspaced bolt for +$110) ($387) (Total: $497)
- Patriot Valley Arms - Osprey 18” 6 ARC barrel with rifle +2 ($399) (add headspaced Rubber City bolt for $125) (Total: $524)
- Shaw 18” HBAR rifle length .750” barrel ($200)
- Proof Research 18” (rifle +1) barrel with muzzle threads (with JP headspaced bolt?) ($489)
- Proof 16” 6 ARC Rifle length (# 128664) ($480)
- Bartlein 6 ARC barrel with muzzle threads & cerakote (+$60 for headspaced bolt) ($792)
- Odin works 18” barrel ($?)
- Rexus 18” 6 ARC Heavy profile Rifle Length Chrome Moly Nitrided Barrel ($165)
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Haha ok. Never used one but will make a note of that. Was there anything specific about them you don’t like?
My 25 Quartermoor shoots great. I have read varying opinions on here and seem inconsistent barrels.
Also read the same on Shaw but again, I had a 6 ARC that was very accurate and consistent with 5 and 10 round groups. Only sold it to get a Proof CF, which frankly, isn’t anymore accurate. Or at least I’m not.
No need to play he said she said. Show me pictures of McGowan's threads. Show me pictures of their machine work.
And they made three of those barrels like that for me. I still have two of them under my bench. And those were replacement for a used barrel I bought of theirs that had out of spec threads on both ends. So that's 4.
And I have an ar15 barrel from them with similar looking muzzle threads and the indexing pin on the barrel extention stuck up about 1/4" past the lip. It shoots good though. Kinda scary to wonder if the thread interface with barrel extention is safe. So that's 5. I saw one in the PX with threads like mine and asked when it was built and it was 2019 or 2020. So that's 6, built over a 5 year time frame.
And they made three of those barrels like that for me. I still have two of them under my bench. And those were replacement for a used barrel I bought of theirs that had out of spec threads on both ends. So that's 4.
And I have an ar15 barrel from them with similar looking muzzle threads and the indexing pin on the barrel extention stuck up about 1/4" past the lip. It shoots good though. Kinda scary to wonder if the thread interface with barrel extention is safe. So that's 5. I saw one in the PX with threads like mine and asked when it was built and it was 2019 or 2020. So that's 6, built over a 5 year time frame.
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I have a 6.5 grendel I put together in about 2017 and I'm pretty sure the throat is worn out. I used to run 123sst's in it pretty hot and nowI run Sierra TMK 107 handloads. It gradually stopped grouping nicely so I'm going to swap the barrel out. Current is a barrel and bolt from Faxon, 416r 5r fluted and black nitrided. I use that one for out to 750 and may try some local gas gun matches that run 1100 max. Trying to get as good of precision as I can for that price range. Heavy profile isn't mandatory but don't want pencil.
Shoot better than what? 0.732 MOA. Ok cool guy. Just because your barrels are shit paperweights, that for some reason you’re still holding on to, doesn’t mean they all are. That’s the point.
Yes, shoot better than 3/4 moa. Consistently, like the dudes that owned them would have cropped that group out of the picture, not cherry picked it.
You didn't make a point. You continued to play he said she said.
So those pictures of their machine work....
Who gives a shit what the lands look like if the barrel shoots. You apparently. There’s threads and threads on long range hunting and here with plenty of anecdotal stories that have had positive experiences. Many where they felt the barrel had some internal flaws. Ultimately, they too didn’t give a shit because the barrel shot great. Your anecdotal story and barrel pics don’t equate to shit in the tens of thousands of barrels probably that McGowan has produced.Yes, shoot better than 3/4 moa. Consistently like the dudes that owned them would have cropped that group out of the picture, not cherry picked it.
You didn't make a point. You continued to play he said she said.
So those pictures of their machine work....
Internal flaws.Who gives a shit what the lands look like if the barrel shoots. You apparently. There’s threads and threads on long range hunting and here with plenty of anecdotal stories that have had positive experiences. Many where they felt the barrel had some internal flaws. Ultimately, they too didn’t give a shit because the barrel shot great. Your anecdotal story and barrel pics don’t equate to shit in the tens of thousands of barrels probably that McGowan has produced.
Probably produced.
Here is some more awful threading on a McGowen barrel being sold on ebay. There are actually two just the same on there. For those that don't know, threads should not be sharp like that.
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Will have my 14.5” Noveske barreled upper back next week. Swapped out the gas block to a Superlative Arms as I’m starting with a 7.62 RC2 and I’m really getting sick of being gassed out. This is for run and gun so the short, light barrel was a compromise to keep the weight and length in line with my URGI~ish uppers.
I’m being a little lazy as this thread is up to 74 pages, but has anyone worked up loads with 95-107 gr for these 14.5” 7 twist barrels?
I have 8208 XBR, MR-2000, Varget, Tac, AR-Comp, RL15.5, CFE223 and LEVERevolution on hand to test in Nosler cases. Would love to hear your experience. Hoping to get 2500 fps and 1moa out of the cheap Hornaday 105 BTHP or 107 SMKs, but would also be happy to use 95 SMK or TMKs.
Appreciate any feedback. DMR match is mid-October so I’ve not got a ton of lead time.
I’m being a little lazy as this thread is up to 74 pages, but has anyone worked up loads with 95-107 gr for these 14.5” 7 twist barrels?
I have 8208 XBR, MR-2000, Varget, Tac, AR-Comp, RL15.5, CFE223 and LEVERevolution on hand to test in Nosler cases. Would love to hear your experience. Hoping to get 2500 fps and 1moa out of the cheap Hornaday 105 BTHP or 107 SMKs, but would also be happy to use 95 SMK or TMKs.
Appreciate any feedback. DMR match is mid-October so I’ve not got a ton of lead time.
With 107 SMK's in an 18" barrel, Alpha brass, 29.4gr 2000-MR @2.260" I was able to get avg fps of 2,539; SD 12; ES 45. Group size was .941 MOA (10 shots).
As a point of reference the max charge for 2000-MR in the Hornady load data (108-110gr bullets) is 29.6gr and with 14" barrel they got 2355 @ 2.245" COAL.
I’m hoping CFE or Leverevo works as Allient powders have gone to ludicrous prices.
If I need to step bullet weight down into the 90s to balance performance out to 800 yards or so, so be it. I just shoot 107s in my Dashers so it’s easy to buy bulk.
Have you checked the fired H20 capacity for the Alpha 6 ARC?? I'm curious if it's giving up anything capacity wise. Lapua grendel formed to ARC is within .1gr of Hornady brass.
Yeah, fired H2O capcity on my batch of Alpha brass was 34.5 grains.
I have seen a couple guys say they went back to Varget rather than dealing with ball powder. I have some lever but I haven't used any yet.
I get pretty good velocity and accuracy with mp501, which is another ball powder. The top group is my 16" cmmg with mp501 and 100g Speers. The bott9m group is mp501 with 95smk in my 22". The first shot out to the right was just after patching it out with oil after not shooting it since last year. The 16" CMMG barrel is MOA. The 22" shoots better, it's an xcaliber built barrel.
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Agreed, I think 6ARC shines in the AR platform with 80s. Stupid accurate and a laser. So easy to shoot tiny from the start..
I had 34.8gr Hornady 6 ARC & 34.7gr Lapua Grendel formed to 6ARC
I always loaded Lever for my 6ARC gasser. That gun is down now due too #2 Rainier extension taking a shit. Have a Craddock RTR sitting on the bench & finally machined the handguard for gas block clearance last night. The RTR is only + 1" instead of the +2" I'd been running.
Meanwhile I did get good speed in the bolt gun with a temp stable stick powder. 26" barrel, 106 Atips @2.380", cci#41, & 28.3gr Vit N540 = 2826fps. Looking forward to trying the N540 in the gasser with 95 Berger VLD's.
Meanwhile I did get good speed in the bolt gun with a temp stable stick powder. 26" barrel, 106 Atips @2.380", cci#41, & 28.3gr Vit N540 = 2826fps. Looking forward to trying the N540 in the gasser with 95 Berger VLD's.
If you haven't checked it out yet there's some good VV 6 ARC gas gun load data here:
Vihtavuori
Not exactly what you're looking for but they have data for 87 berger VLD's:
and 95 Berger classic hunter:
My shortcut now for starting load development for a new upper or new bullets in the 95gr - 108gr range is to load up 5 each of 29.1gr, 29.3gr and 29.5grs of LVR... usually something in there shoots. I've been using Hornady and Starline brass, the capacity you posted for Alpha is pretty close to what I've measured though.
I would add Satern to the list. I bought one to see how I liked the round with thoughts of upgrading and it shoots really well, so have not felt the need. .6-.8 MOA consistantly.
thanks for the heads up. I've heard mixed things about Satern barrels. Some people love them others think they are trash, but that pretty much applies to anything these days lol
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