New 6mm Advanced Rifle Cartridge

Yondering

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Funny you have been using small based dies all this time and didn't know it but you criticize others for buying small base dies.
Anyone can find this info with just a few phone calls. Call every die company and ask to speak to the engineer. Ask them what their target design diameter for the dies are. Yes they all have tolerances and may be a little larger or small but they draw the dies to be made a certain size(target dia). Ben At Hornady has been making custom dies for me 50 at a time for years and Lonnie before him going back 15 years. Either on of those guys can tell you in 2 seconds .004 under minimum chamber size.
Or instead of asking someone else on the phone, get out to the shop and measure what they actually are.

My Hornady 223 dies measure exactly the same at the base as my standard RCBS 223 dies. Not "small base" RCBS dies, but standard. My 6 PPC and Grendel die sets show the same results as well. The actual SMALL BASE dies are the only ones that measure smaller there. (Had to type that in caps so you could figure out which end of the cartridge it refers to.) We are not talking about shoulder diameter here, that is not the issue.

The Hornady dies I have are slightly smaller at the shoulder, but NOT at the base. That doesn't make them small base dies. Are you confused what "small base" means? It sure doesn't have anything to do with the shoulder of fireform rounds.
 
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Yondering

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Can i use a 6mm PPC Neck Sizing Die to resize the 6mm ARC Brass? I have a Uintah Precision Upper on a AR-15 Lower. I have taken the fired brass and head space measures at 1.1910 (SAAMI Spec: 1.1901 - 1.2001) Fired Brass fits in a Wilson 6mm ARC Case Gauge. i'm assuming i have a tight chamber and all i really need to do is re-size the neck. Fired case does chamber in the action without any effort. I have reached out to Forester and they said they will get back to me.
If it's for an AR, you're really going to want a FL die set (and yes, 6PPC dies work great). It doesn't matter if the chamber is "tight" or not; brass and steel stretch under pressure and you're going to need to push some of that brass back for clearance in an autoloader. You might get away with it for one or two reloads, but not much more than that unless you're using really mild loads.
If it's for a bolt action, carry on.
 

trdjohn

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@Dino11 , what weight of buffer are you running? Adjustable gas block? If so how much gas does it need? Is it under or over gassed, or just right? I've got the same 18" barrel. I finally got an xl gas tube from JSE, the one odin sent out is still sitting in Idaho post office (odin forgot to include it in original order). I assembled the barrel into an upper today but it's raining here and too many errands on list to get to range this weekend. Great shooting on those groups, now I'm pumped to get mine out to see how it does.
 

Constructor

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Or instead of asking someone else on the phone, get out to the shop and measure what they actually are.

My Hornady 223 dies measure exactly the same at the base as my standard RCBS 223 dies. Not "small base" RCBS dies, but standard. My 6 PPC and Grendel die sets show the same results as well. The actual SMALL BASE dies are the only ones that measure smaller there. (Had to type that in caps so you could figure out which end of the cartridge it refers to.) We are not talking about shoulder diameter here, that is not the issue.

The Hornady dies I have are slightly smaller at the shoulder, but NOT at the base. That doesn't make them small base dies. Are you confused what "small base" means? It sure doesn't have anything to do with the shoulder of fireform rounds.
I did idiot, that is why I ended up calling all of the companies that made the dies. Hornady dies were sizing smaller than all of the other FL sets and Redding wasn't sizing the brass small enough. Reading comprehension 101 there Dan.
 
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Triple D

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Nice, the 6ARC showing its 6PPC lineage. This is what I expect out of this cartridge! Nice shooting @Dino11 and great work on that barrel Odin.
You’re expecting 1/3 moa from a gas gun with factory ammo? If that’s a legit result, Hornady and Odin have a good thing going. Most ppl have trouble getting half moa groups with a gas gun and handloads, so forgive my skepticism.
 

ormandj

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You’re expecting 1/3 moa from a gas gun with factory ammo? If that’s a legit result, Hornady and Odin have a good thing going. Most ppl have trouble getting half moa groups with a gas gun and handloads, so forgive my skepticism.
I read it as he expects good accuracy out of a cartridge based on the PPC, not that he expects 1/3 MOA or better all the time from every rifle and ammunition combination, which is obviously unlikely.
 

hertz654

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I just got an invoice/shipping notice from Brownells that the Faxon 20" barrel I ordered right out the gate (June 2) is supposed to ship tomorrow. It will probably take me some time to get my 6mm ARC upper built, but its good to see at least one necessary part is rolling in.
 

jbailey

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You’re expecting 1/3 moa from a gas gun with factory ammo? If that’s a legit result, Hornady and Odin have a good thing going. Most ppl have trouble getting half moa groups with a gas gun and handloads, so forgive my skepticism.
No doubt that a 6PPC lineage cartridge should be able to offer precision of that level, although precision will be driven by the 'weakest link' in the system: shooter, rifle, cartridge, with shooter being the biggest variable. This is especially true at a distance like 300yds, where MV variation isn't going to be a major factor in the vertical dispersion. Also the 300yd difference between 1/3 moa and 1/2 moa is only about 0.5" and I would say we don't have enough info to say if this is a 1/3 moa or 1/2 moa 'system'. I would say we do have enough to say its 'nicely under 1 moa', which is what I would want.

My 6.5 Grendel, another 6PPC lineage cartridge, with handloads and a barrel from Satern, could print these types of groups at 300, when the nut behind the gun was up to it (which wasn't often).
 

Triple D

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I would say we do have enough to say its 'nicely under 1 moa', which is what I would want.
If it was fired at 300yds and not 100yds, I would agree.

Something just seems off for this to be 300yds with the factory 105’s. Maybe jamming them into the lands several thou lead to better than anticipated precision, but to have so many rds (6 based on the other targets) go into the same hole at 300yds, with an AR, with factory ammo and a Viper HST scope just seems a bit hard to believe.

Those 6 shots are what, <.1moa? Just doesn’t pass the smell test.
 
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Hootiewho

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I’m going to ask a stupid question, as I really don’t know.

Say you want to run a LMT rifle length upper and have a barrel done in 6mm ARC for that upper. Say you have a SS .204 ruger or 556 barrel you are willing to use to rob the barrel extension and gas block off of.

Will that barrel extension work with the 6mm ARC or 6.5 Grendel bolt or do the 2 have a proprietary barrel extension?
 

Trippm

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Proof 18” SS just shipped! Now I just need some ammo... and maybe a rifle +1 gas tube. Both of which are like hens teeth it seems.
 

trdjohn

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Proof 18” SS just shipped! Now I just need some ammo... and maybe a rifle +1 gas tube. Both of which are like hens teeth it seems.
I think white oak had +1 gas tubes, have to hunt a bit for them in their website
 

Trippm

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WOA has the +1 on back order

Altus has the 18”SS proof.

unfortunately, nobody chimed in on ammo
 

SWFShooter

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So I should cancel the white oak order I placed 3 seconds ago... figures
Did White Oak start making 6mm ARC barrels? Hollinger posted a statement that he would not be making 6mm ARC barrels, he doesn't like the Grendel bolt.
 

scrumpdeleos

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What are you guys seeing for prices for 6mm arc? It seems it can range from about $1 a shot to $1.50 depending on where you look (ELD rounds).
 

Dino11

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I purchased some awhile back, 200 rounds for $197.00 shipped. But would never order from the folks again. They lost the shipment and wanted to refund my money. I told them that the shipment was not lost it never left the warehouse. I get E-mail notices any time something is shipped to my address, or company name. They finally owned up to it. They basically sold me something they did not have. I told them I was going to file a suit with the Attorney General, they found my ammo pretty quick after that and shipped it to me 2 day. But it did not come from their warehouse.
 

scrumpdeleos

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I purchased some awhile back, 200 rounds for $197.00 shipped. But would never order from the folks again. They lost the shipment and wanted to refund my money. I told them that the shipment was not lost it never left the warehouse. I get E-mail notices any time something is shipped to my address, or company name. They finally owned up to it. They basically sold me something they did not have. I told them I was going to file a suit with the Attorney General, they found my ammo pretty quick after that and shipped it to me 2 day. But it did not come from their warehouse.
Where did you order from?
 

Dino11

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Ammo Supply Warehouse, It wouldn't have been to bad a deal except they said it was in stock, immediately took my funds, then lied to me about it for about a week. I did not tell them in the beginning that I had a business account with UPS and get notices on all shipments.
 

tomcatfan

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I've got 200 rounds on back order from Midwest. I got an email that 40 rounds of the 105 Hornady Blk ammo was in, but I've not heard anything about the 108 ELD match.
 

db2000

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It’s physically in stock at GAP as of this post.
 

tomcatfan

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And GAP is QUICK to ship. I ordered three boxes early this week, it arrived today. The quickest turn around for an order I've seen in a long time.
 

trdjohn

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And GAP is QUICK to ship. I ordered three boxes early this week, it arrived today. The quickest turn around for an order I've seen in a long time.
likewise, ordered Monday late afternoon, fedex just dropped off this afternoon...SGammo has 108 match in stock fyi, $25/box
 
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thestoicmarcusaurelius

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Might have missed it but do we know what a realistic velocity from a 16" small frame ar barrel with the 108 ELDM Ammo would be? What I've seen so far indicates 2500FPS for the 108ELDM in a 16" barrel.

Based on drunken back of the napkin calculations with a buddy, a 108ELDM at 2500FPS using a .536 G1 BC wouldn't pass a 73ELDM at 2700FPS using a .398 G1 BC for drop until 700 yards? Looks like it would have a 400 foot pound of energy advantage at all distances out to 700 yards then more after 700 yards.
 
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ormandj

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Might have missed it but do we know what a realistic velocity from a 16" small frame ar barrel with the 108 ELDM Ammo would be? What I've seen so far indicates 2500FPS for the 108ELDM in a 16" barrel.

Based on drunken back of the napkin calculations with a buddy, a 108ELDM at 2500FPS wouldn't pass a 73ELDM at 2700FPS for drop until 700 yards? Looks like it would have a 400 foot pound of energy advantage at all distances out to 700 yards then more after 700 yards.

Velocity with factory ammo at the bottom in different barre lengths. Go fire up 4DOF on Hornady’s website and plug in the two cartridges and compare. Also, remember, drop doesn’t really matter if you have ballistic tables accurate for your conditions and can run your scope. It’s windage that you really care about.
 
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thestoicmarcusaurelius

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Velocity with factory ammo at the bottom in different barre lengths. Go fire up 4DOF on Hornady’s website and plug in the two cartridges and compare. Also, remember, drop doesn’t really matter if you have ballistic tables accurate for your conditions and can run your scope. It’s windage that you really care about.
At the above numbers from my previous post, drunken numbers would be .3 mil advantage at 500 yards for 10MPH wind at 90 degrees for the 6ARC and 1.1 mil relative advantage at 1000 yards
 

holdstillplease

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I'm hoping patience will be a virtue with this cartridge. I skipped the barrel & ammo ordering bandwagon the first week of June and ordered my 7th X-Caliber barrel, due around October 1, and with Hornady's bullet problems lately I'm hoping that waiting until my barrel is shipped before I order ammo will be the right choice. Happy to see it's shooting well for early adopters though.
 

SBRSarge

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Got a link?

I don’t reload, haven’t for 25 or so years, but this cartridge is starting to rekindle the desire.
 

Ledzep

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Might have missed it but do we know what a realistic velocity from a 16" small frame ar barrel with the 108 ELDM Ammo would be? What I've seen so far indicates 2500FPS for the 108ELDM in a 16" barrel.

Based on drunken back of the napkin calculations with a buddy, a 108ELDM at 2500FPS using a .536 G1 BC wouldn't pass a 73ELDM at 2700FPS using a .398 G1 BC for drop until 700 yards? Looks like it would have a 400 foot pound of energy advantage at all distances out to 700 yards then more after 700 yards.
More like 2525-2550 with the 16" ARC.

I get the 6 ARC trajectory overtaking the 73 ELD @2700 at ~600yd for elevation. It's basically identical up to that point, with considerably less wind drift past 300yd, and a lot more energy throughout, and supersonic range that's 200+yd further.

In fairness, I don't think the 73 ELD load will still be going 2700fps in a 16" barrel. The box says 2790 from a 24" barrel, probably closer to 2600-2650 in a 16", which would open the gap considerably. Unless you want to go hand load for hand load, but there are better 6mm pills to work with.
 

thestoicmarcusaurelius

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More like 2525-2550 with the 16" ARC.

I get the 6 ARC trajectory overtaking the 73 ELD @2700 at ~600yd for elevation. It's basically identical up to that point, with considerably less wind drift past 300yd, and a lot more energy throughout, and supersonic range that's 200+yd further.

In fairness, I don't think the 73 ELD load will still be going 2700fps in a 16" barrel. The box says 2790 from a 24" barrel, probably closer to 2600-2650 in a 16", which would open the gap considerably. Unless you want to go hand load for hand load, but there are better 6mm pills to work with.
I agree that with reloads in excess of 52ksi that 6mmARC might pull ahead faster but if it is factory compared to factory with the 5.56 75BTHP Super Performance load with the 20" barrel and the 6ARC 108ELDM load with the 24" barrel the trajectory is very close out to 500 yards and remains the same way if you assume 25FPS/inch loss of velocity for each if we were trying to approximate velocity in a 16" barrel.2020-08-12.png2020-08-12 (2).png



 
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Ledzep

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I agree that with reloads in excess of 52ksi that 6mmARC might pull ahead faster but if it is factory compared to factory with the 5.56 75BTHP Super Performance load with the 20" barrel and the 6ARC 108ELDM load with the 24" barrel the trajectory is very close out to 500 yards and remains the same way if you assume 25FPS/inch loss of velocity for each if we were trying to approximate velocity in a 16" barrel.
I don't mean anything about exceeding 52ksi. In an AR-15 it's asking for broken lugs. I mean shooting different bullets. Match bullet weight and barrel length and the 6 ARC is going to be faster. Match the .223's BC and barrel length and the ARC is going to have ~20% more bullet mass and likely slightly more velocity.
 
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thestoicmarcusaurelius

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I don't mean anything about exceeding 52ksi. In an AR-15 it's asking for broken lugs. I mean shooting different bullets. Match bullet weight and barrel length and the 6 ARC is going to be faster. Match the .223's BC and barrel length and the ARC is going to have ~20% more bullet mass and likely slightly more velocity.
Have any links or anything to the combinations that you are referring to in 6ARC from a 16" barrel where it would have a muzzle velocity higher than 2700FPS from a 105 grain or higher bullet with a 52ksi or under load?

Don't get me wrong, I'm all in on the idea 6ARC and have a barrel and bolt and mags for one on the way. I really like it for a semi light weight / semi precision small frame ar setup where you still have enough energy to ethically harvest a deer out to a few hundred yards but is also light enough to be used for carbine classes.

Just trying to be realistic about what to expect. Maybe you have found a great combination that other people don't know about.
 
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