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New 6mm Advanced Rifle Cartridge
- Thread starter Gtscotty
- Start date
My thoughts/hopes are that this was cooked up as a competitor to the NGSW program... maybe in a slightly bigger ar15 variant that would be able to accept PMAGs like the LWRC SiX8?
That would be right up their alley and i would be 100% ok with it lol
It would be a fantastic competitor in the NGSW program. If the military is OK with "proof-round" pressure levels in standard infantry weapons, then a very high-pressure 6mmARC with either a polymer case or SIG's brass body/stainless steel case head is the cartridge to beat — assuming they want to retain the constraints of the legacy AR platform.
A 6mm 105gr bullet is light recoil, compact, fantastic external ballistics, solid wound ballistics (if 5.56 has been "good enough" all these decades, then a 105gr 6mm is even nastier), logistics-friendly, and a long carbide steel or tungsten penetrator within the long bullet at those very high pressures and velocities just might give them the improved body armor penetration they seek. The longish bullets also lend themselves to a tracer round. Probably the reason they choose to experiment with 6mm in the '70s with the 6mm SAW.
A 6mm 105gr bullet is light recoil, compact, fantastic external ballistics, solid wound ballistics (if 5.56 has been "good enough" all these decades, then a 105gr 6mm is even nastier), logistics-friendly, and a long carbide steel or tungsten penetrator within the long bullet at those very high pressures and velocities just might give them the improved body armor penetration they seek. The longish bullets also lend themselves to a tracer round. Probably the reason they choose to experiment with 6mm in the '70s with the 6mm SAW.
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Interesting. Care to share some data? I'm pretty happy with H4895 and the 87 vmax in my 243 LBC, but I'm always interested to see what others are doing.
It is based off the 6PPC. That cartridge a standard in bench rest. Should be very easy to load for.
No easier or harder than most other cartridges. To follow on CanSniper's comment - you can even use off the shelf 6mm PPC dies, as I'm doing for the 243 LBC. Based on the dimensions of this 6mm ARC, it won't be any different, although you'll be able to buy specific ARC dies I'm sure, and that will give us wildcatters yet another die choice.
I often wonder what people are really asking with that question about "easy to load for". Component availability maybe? There's not much difference in reloading most cartridges, as long as the bullets aren't tiny (17 cal) and you don't have to turn necks or make brass from a very different parent cartridge.
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Sure, although I haven't used the 87 Vmax; I'm mostly using heavy bullets, with some 70gr TNT for blasting just because I have a bunch.
Keep in mind all of the Lever data you'll find at this point is wildcatter's edjucated guesses; this is what works in my rifle and may or may not in yours. Also keep in mind there can be a significant difference with different brands of brass.
105gr Hornady BTHP, 2.235" OAL
Lapua brass
CCI 450 primers
Leverevolution 31.3gr - 2853 fps 24" brl - 2764 fps 19" brl - maybe max? but good brass life in my rifles
That 105gr BTHP was tested for seating depth first, with charges ranging from 30.0gr to 31.3gr for each seating depth; 2.235" was by far the best and shot pretty well despite the varying powder charges, better than any load I tried with Varget and this bullet. For general shooting I'm using 31.0gr (2835 fps in my 24"), that gives some leeway for velocity variations at different temps.
A couple other loads:
100gr SGK, 2.154" OAL
Formed 7.62x39 brass, PMC & R-P
CCI 200 primers
Leverevolution 30.4gr - 2856 fps 24" brl - 2790 fps 19" brl
That one is my standard load for the 19" gun at this point, since it's more of a hunting or "walking varminter" setup. (I made the barrel from a 20" BHW blank, and cut it as a medium-light tapered octagon barrel just to be different; total weight is just under 8 lb ready to shoot.)
70gr Speer TNT (good cheap varmint bullet), 2.255" OAL
Formed 7.62x39 brass, PMC & R-P
CCI 200 primers
Leverevolution 35.0gr - 3517 fps 24" brl - 3409 fps 19" brl
This one is not the best choice for Lever; it's maxed out for case fill and needs to be tapped to settle the powder in the case. However it does show the versatility of Lever as a good powder for this cartridge, when compared to what other powders will do with the same bullet.
One final note on Lever as a powder choice - with almost every load, I've noticed a consistent pattern: best accuracy has been obtained by
1) finding the max charge (at the longest possible OAL), and then
2) finding the optimum seating depth.
Lever likes to be pushed to max, and you'll generally find a 0.5-0.8gr window at max where charge variations do not affect accuracy much if at all. This formula has consistently given me better accuracy than most other powders, in a wide range of cartridges that use this burn rate, such as:
- 20 Tactical
- 223 Wylde / 5.56
- 243 LBC
- 6.5 Grendel
- 358 Herrett AR (my own wildcat)
- 35 Remington
I still need to test it in 308 and 35 Whelen, and expect similar results in both.
Long post, but hope that helps.
this looks like an ideal cartridge to cross-over between an AR-15 platform and a bolt-gun for p-dogs/coyotes. I was intrigued by the 6GT [and 6Dasher w/Alpha brass availability], but will now wait to see how this develops. To me, its always a shame when somebody has been doing something similar at the privateer level, but it doesn't take hold until a major manufacturer gets onboard with something similar.
I will be interested in this versus the 6.5 grendel. Would I take a bit better ballistics or a heavier bullet?
i do like my heavier bullets
i do like my heavier bullets
Hornady TC25166 6mm Arc FL Rougher * Company Only* - Pacific Tool and Gauge
pacifictoolandgauge.com
hopefully we see something soon
Hornady TC25166 6mm Arc FL Rougher * Company Only* - Pacific Tool and Gauge
hopefully we see something soon
Interesting, I wonder what the description means when it says the product page is for "internal use"? It has a price small looks like you can add it to your cart.
Edit: maybe this is the page meant for customers?
6MM ARC (Advanced Rifle Cartridge) - Pacific Tool and Gauge
6MM ARC (Advanced Rifle Cartridge)
pacifictoolandgauge.com
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Not yet. I ordered another 243lbc. If 6ARC Ammo will safely shoot in it, great. If not, I’m no worse off.
Probably waiting for COVID to blow over to give it a proper hyped up release... which I am down for this sounds like something I would really like and the better it catches on the more stuff that will be available.
Yeah, I was looking around today and it seams no one has any product support for it yet. I was hoping for this to come to life as I've been wanting to build an AR15 in 6mm.
I've got a couple of spare AR-15 bolt carrier groups so I found a smokin' deal online for just the 6.5 Grendel bolt heads to convert to this cartridge if/when it gets released. Hopefully aftermarket barrels come along shortly thereafter.
Interesting. I'm guessing varget would be a popular powder for this. I have so much h4350 stored up that I wish there was an ar15 sized caliber that was optimized to use it...I wonder if this necked down to 22 would suffice 
might have to fire up the 'ol QuickLoad
might have to fire up the 'ol QuickLoadInteresting. I'm guessing varget would be a popular powder for this. I have so much h4350 stored up that I wish there was an ar15 sized caliber that was optimized to use it...I wonder if this necked down to 22 would suffice
Varget is generally considered too bulky for the 6.5G, so I would think that would hold true with this cartridge as well. Seems like the longer sticks just take up too much room to get the speed you can with other powders.
8208, CFE223, Leverlution and others in that burn rate are powders I'm seeing most often used while I'm researching reloading for my 6.5G. Not saying those will also be the go to powders with the lighter 6mm bullets, but suspect they'll be good starting points.
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In terms of powder for this thing, I have had good luck with benchmark in my 6mm grendel variant.
What bullet weight have you been using Benchmark with?
Not expecting there to be a direct correlation between the 6.5G and 6ARC when it comes to better powders for light and heavy for caliber bullets, but it'll be interesting to see if there is a bit of a trend. For instance, my research into 6.5G loading shows the faster Benchmark being used up until the ~100gr projectiles, with 8208XBR and Power Pro Varmint doing a little better with the 108-123gr types. Getting into the 129gr ABLR and 130gr SMK loads it looks like AR Comp and H4895 start to become favorites. This is by no means an exhaustive list, but just the ones I've been making mental notes of as I keep some of them around for other purposes as well.
There's certainly no one powder to rule 6.5G reloading, and I hope/suspect the 6ARC will be similar in that a large number of powders will work well with a given bullet weight.
I'm just laying back in the tall grass and keeping an eye on this one...
If affordable AR barrels come out in this chambering; I may bite.
I'm thinking about the case base diameter and AR bolts. I already have one broken extractor from pushing the pressure boundaries with the 6.5G.
Greg
If affordable AR barrels come out in this chambering; I may bite.
I'm thinking about the case base diameter and AR bolts. I already have one broken extractor from pushing the pressure boundaries with the 6.5G.
Greg
The ARC will not work in a LBC, headspace would be .030" larger than it should be.
Same here. Hornady has a product announcement June 3rd. Will see what comes from that. I've pushed the 6.5G hard and broken a bolt head so would be nice to see this 6mm ARC come through.
I'm shooting a 6mm predator, which is a necked down grendel. Using benchmark for 58 gr vmax and 90 gr gamechangers. It's a little bit lower fps compared to 8208, but not as hard to find either. Supposed to be more temp stable too.
Will see next week if it’s this 6mm ARC cartridge or something like another safe or miscellaneous product or just some new cheap plinker ammo.
What barrel length for your Predator?
What speeds are you seeing wth both projos for XBR and Benchmark?
22" barrel, I'll have to check on the velocities.
The video is an ARC tease for sure... The shit floating around while the guy talks are parts of the letters A, R, and C....
The video is an ARC tease for sure... The shit floating around while the guy talks are parts of the letters A, R, and C....
that's some mighty fine detective work, Sgt Friday. I watched the vid and didn't really pay much attention to the letters floating around in the video. I don't think advertising is very effective on me; but endorsement is a different ballgame => when lowlight starts to shoot the 6mm ARC, then I'll be sold hook, line and sinker!
Benchmark and 8208 XBR are very similar; close enough that the bullet weight distinction you mentioned above doesn't really apply. You'd be hard pressed to find two other powders that are more similar but not actually the same.
I use both and have found for the same charges Benchmark gives slightly higher velocity (which makes sense, being faster burn rate). I've also found that in pretty much any application where 8208 is good, Benchmark also works well, and vise versa.
If you want top velocity from your Grendel or 6mm variant though, Leverevolution is your huckleberry. Nothing else I've found comes close, and definitely not while delivering the same accuracy. It does give up some temp sensitivity to powders like 8208 and Benchmark though. With the 129 ABLR in my 12.5" Grendel, Lever is THE powder to use; the stick powders all give up about 200 fps or more in my testing. It also gives the best accuracy at top velocity with the 105gr BTHP in my 19" and 24" 243 LBC rifles.
Alrighty,
8208 XBR, 90 gr game changer 2930 fps
8208 XBR, 58 VMAX 3420 fps
Benchmark, 90 game changer 2900 fps
Benchmark, 58 gr vmax 3450
Those were just as high as I went, starting to show decent pressure so I stopped. The accurate ones were about 75-100 fps slower.
I guess I didn't remember right earlier...
8208 XBR, 90 gr game changer 2930 fps
8208 XBR, 58 VMAX 3420 fps
Benchmark, 90 game changer 2900 fps
Benchmark, 58 gr vmax 3450
Those were just as high as I went, starting to show decent pressure so I stopped. The accurate ones were about 75-100 fps slower.
I guess I didn't remember right earlier...
I'm this close to picking up an 8lb keg of Lever as I'll be starting 6.5G load dev soon, and also have a 30-30 with an on again off again load development relationship. Problem is I keep so much 8208XBR around for 77gr .223 it just seems like the easy button to keep one less keg of powder around.
Man, everytime I turn around there is a new caliber that I think I MUST have. I've been eyeballing a .243 LBC for a while, but seems the 6mmARC would have more/easier component availability if it ever makes it to production.
You seem sure this is going to kick off.
Anything you would like to share? Lol
If I can get large frame performance (or close to it) from a small frame 6mm AR, I am in. Hoping the big barrel builders get on board and the factory ammo delivers. That will help traction. Large frame ARs are a bit clumsy. You can build a much more comfortable and shootable rifle in a small frame as long as the cartridge performance is there.
I shoot the 6mm predator right next to my 6.5 creed bolt gun about very weekend. with 90s and 143s, they are really damn close for vertical. Obviously energy and windage will be a bit different, but the 6mm shoots just as flat, and a little flatter up close, as the creed.
No inside info. I just know it when I see it. This is real.
6.5 Grendel is a hunting cartridge that can be used for targets. 6mmARC is a target cartridge that can be used for hunting.
ALL AR15 and ALL GOOD.
I’ve got a 16” Grendel for hunting and had been considering a 224 for targets and steel but I’ll wait for Hornady to roll this out. Really interested for factory ammo numbers.
The factory 107 TMKs that I shoot are in the 2525 neighborhood. Let me get faster than that with a 6mm and I’m game
The factory 107 TMKs that I shoot are in the 2525 neighborhood. Let me get faster than that with a 6mm and I’m game
Probably looking at similar velocity with a 105-108 at 16" (2500-2550fps), but BC will be considerably better.
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