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So I got in some of Horandy's factory "Black" 6mm ARC ammo (105 gr BTHP) and their "Match" 6mm ARC ammo (108 gr ELD) and after a go over of it before starting actual range testing (i.e. shooting them), all I am going to say is Hmmmm!
The "Black" ammo is loaded at right around 2.200" OAL which gives the bullet a jump of just about .040" to the lands on a SAAMI 6mm ARC chamber (at least the one I have).
The "Match" ammo is loaded right around 2.250" OAL which also gives the bullet a jump of just about .040" to the lands on the SAAMI 6mm ARC chamber (at least the one I have).
I pulled down a number of cartridges to measure the powder loads and just to see what was going on inside and here's what I found:
Both the "Black" and the "Match" are loaded with a ball powder that looks like a dead ringer for Hodgdon's CFE223 and the loadings also bespeak of a powder of a similar burn rate. In addition, the loads of both are under heavy compression. To get the powder out of the cases after pulling the bullets, I had to hold each case horizontally over a metal cup and insert a wooden toothpick in the case as I spun it to break up the solid chunk of powder in the case caused by the compression. Even then, the powder came out with clumps of the powder stuck together from compression. IMO - not exactly the recipe for accurate loadings (i.e. ball powder under heavy compression).
The loading of the "Black" varied from 30.12 gr to 30.38 gr..
The loadings of the "Match" varied from 30.58 gr to 30.60 gr..
New factory brass was just under the "go" headspace dimension which means if a "go" gage goes in your chamber, so will the ammo, headspace wise. The brass length of the cases hovered around 1.485" OAL.
The 105 gr bullets of the "Black" were right around 1.225" in OAL, which means that when the cartridge is loaded at 2.200" OAL you have around .715" of the bullet sticking out of the brass and .510" of the bullet back in the case. Since the neck of the brass is right around .230" long, that put's another .280" of bullet back beyond the neck/shoulder junction - - ergo why there is heavy compression of the powder. As an aside, the pulled down powder, when poured back in the case, after pull down, sits right about at the neck/shoulder junction.
Similar results with the 108 ELD bullet. The 108's of the "Match" were right around 1.265" in OAL, which means that when the cartridge is loaded at 2.250" OAL you have around .765" of the bullet sticking out of the brass and .500" of the bullet back in the case. Since the neck of the brass is right around .230" long, that puts another .270" of bullet back beyond the neck/shoulder junction - - ergo why there is heavy compression of the powder, especially since the charge for the 108's was greater than for the 105's. Once again, the pulled down powder, when poured back in the case after pull down, sits right about at the neck/shoulder junction.
Just my personal impressions - - I love accurate rifles and accurate ammo is an essential ingredient to them. If the powder is CFE 223, and I believe it is, those are loads we tested in the 6mmAR, but those are not loads we shot or used with the 6mmAR because, while they got the velocity and pressure numbers, they never proved to be consistently accurate. FWIW - I never found heavily compressed loadings of any power to be particularly accurate, and ball powders are not the best for consistent accuracy either IMO.
Now Hornady touts that the 6mm ARC was made up as a cartridge for military use, so I assume it's about man sized targets. I can only say that for real accuracy work in the 6mmAR, despite the testing of numerous powders, we always came back to stick powders, and not under compression at all (if possible).
So I am going to range test these loadings, but I am not optimistic as far as their promise for consistent accuracy - - but we'll see!
Robert
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We have covered some of this here:
https://6mmarc.com/showthread.php?tid=50&page=2
When we called Hornady about the issue they said we could just see at the bullets deeper for the Hornady Black loads.
Most folks are seeing MOA with the Black ammo
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10-26-2020, 01:42 AM
(This post was last modified: 10-26-2020, 02:25 AM by Lemonaid.)
Thanks for the break down! Good info. From the reports of others, factory ammo does pretty good, SD's in the low teens seems common. Velocities are close to advertised. There was/is the gremlin of some barrels being on the short throat side for the initial longer oal factory loads, likely why they are now heavily compressed at 2.200.
In the Hornady gas loads for 103-105 bullets, the closest to 30.0 grains is with Lever at a max of 29.5. It would be a neat experiment to try and duplicate the 105 black load, any takers?
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The more I read about the 6 ARC the more I'm happy I'm not an early adopter. Hornady should have just gone to Robert and agreed to SAAMI the 6mmAR.
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10-26-2020, 12:01 PM
(This post was last modified: 10-26-2020, 12:03 PM by 6mmAR.)
(10-26-2020, 04:23 AM)Biodsl Wrote: The more I read about the 6 ARC the more I'm happy I'm not an early adopter. Hornady should have just gone to Robert and agreed to SAAMI the 6mmAR. I don't get that either - - since Hornady makes brass, I don't understand why they did not stretch the body of the 6mmAR longer and not go the .030" shorter in the body like they did. Made no sense to me. The 6mmAR Turbo has the 6mmAR body stretched .040" (.070" more than the 6mm ARC) and the Turbo 40 has the body stretched .080" (.110" more than the 6mm ARC) and both those cartridges function 100% and they both have increased case capacity (i.e. Turbo 40 is 38 gr of water weight vs. 6mm ARC of 34 gr water weight - like 12% more case capacity - makes a real difference with a smaller case).
Interesting, as a part of our original 6mmAR testing, we did testing with various powders and bullets to find out at what point with a certain load and a certain bullet you started to compress the powder charge. In the 6mmAR with CFE223 powder and 31.5 gr of powder and a Berger 108 BT bullet, the bullet sat comfortably on top of the powder at 2.260" OAL (i.e. magazine length) with no compression. That's what the extra 2 gr of water capacity does in the 6mmAR (i.e. vs the 6mm ARC).
In the 6mmAR, a 108 gr Berger BT sat comfortably on top of 28 gr of H4895 at 2.270" OAL (absolute max mag length with typical magazines for the 6mmAR). At 27.5 gr. of H4895 it sat comfortably just under 2.260" OAL. We normally shoot 27 - 27.5 gr of H4895 magazine feed in the 6mmAR with the 105-108 gr bullets.
I have numerous other powders and bullets measured, but you get the idea. We did this all because accuracy is a key component of loads and we found we needed to stay away from heavily compressed loads in order to keep accuracy. BTW - very lightly compressed loads did not seem to have accuracy issues with stick powders (e.g. 28 gr of RL15/AR Comp with a Berger 108 gr bullet loaded at 2.260" OAL in a 6mmAR is very lightly compressed and has no accuracy issues).
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Give us ALL you have for 90 grain bullets and stick powders - we’d love to try it in 6-ARC now that it is in more folks hands ...
Please
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(10-26-2020, 12:41 PM)Pig_Popper Wrote: Give us ALL you have for 90 grain bullets and stick powders - we’d love to try it in 6-ARC now that it is in more folks hands ...
Please For magazine fed rounds with the bullets in the 90 gr range we did not do any real powder capacity testing because the issue was mainly an issue with the longer 105-108 gr bullets at magazine OAL's. For the 6mm ARC the 90's should run great. Years ago Berger made a 100 gr BTHP bullet (I have a bunch of them) and they would work superbly well in the 6mm ARC since they're a little shorter than the 105-108 gr class of bullets.
For the 90's in the 6mm ARC I would tend to favor H4895, RL15/AR Comp, and N140 (and N540) and maybe XBR-8208.
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With my faxon barrel I measured OAL's for the 105 Bthp-hornady, and I got 2.277".
So in this barrel there is not the 2.200-2.220 limitation. I guess it has a longer throat.
Most of my 100+ gr bullet loads have been with the 103 Eldx (which OAL's for me out to 2.305 btw). With the 103 I've gotten loads of CFE, 2520 and Lever up to 30 grs, probably could have gone higher but haven't as of yet... no appreciable sounds or notice of compression. Most of my powder charges have topped out at the case-neck entry point.
The only bullets I'm seating down at the 2.200 =/- is the 95 sst, with its flat bottom again, no noticeable compression - I load it to 30.1 of Lever, ~2800 ft/s (going off of memory this morning as I sit here).
To echo where I think you're going Rob, for me the sweet spot bullet-wise seems to be long-ish, 90-103 grain bullets, the 90 Tgk, 95 sst and Nosler BT, 103 eldx. Maybe the 100 Tgk but I don't have any of those yet. I also, personally, think to stay away from the barrels with the noted "short-throat" chambers (Proof, Odin), so that you don't have to go 2.200 for the 105 etc's. Dino seems to get good performance out of his Odin however.
105 Black shoots about MOA for me, at 2665 - 20" faxon nitrided barrel.
If I remember correctly the 108 shoots about 2640.
I bought some of both early on to get brass plus see how they did, now I pretty much roll my own. Lever is powder of choice so far.
CFE, Lever and even 2520 look pretty close to me except CFE has a bit more silvery sheen to it. Do you think that stock powder might be a form of 2520 or Lever? Curious mostly.
CFE for me doesn't shoot that well unless you can get up close to or slightly over the 100% fill mark.
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And the 95 SMK's, when I get around to them...
I got the 90 TGK up to 2858 with Varget, 29.8, now this one was close to max I think. Just 1 ladder, more testing to follow.
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10-26-2020, 03:09 PM
(This post was last modified: 10-26-2020, 03:14 PM by Dino11.
Edit Reason: Added content
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I'm going to be loading some ammo in the next couple of days, still prepping the brass. I will tear down a factory 105 and do a weight check and compare the powder to some of the ones I have. I have CFE, Lever, ARComp, and a few others. I will try and duplicate the load if I have the right stuff. I would also like to try H335, I did some .223 heavies the other day and everybody told me it wouldn't work. well the damn things started printing 1 MOA at .4 and .7 grain suggested above max load, as their was no data to go off of. No real signs of pressure except a very slight flattening of CCI 400 primers, the Winchester primer ones had no signs.
I won't be able to get out to the range with these until Saturday because it is going to rain all week. I will keep you all updated as to what I find.
I will shoot these out of my Faxon barrel to keep it on par with everybody else's numbers, that Odin barrel just flat out gets very good velocity numbers
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(10-26-2020, 01:51 PM)grayfox Wrote: And the 95 SMK's, when I get around to them...
I got the 90 TGK up to 2858 with Varget, 29.8, now this one was close to max I think. Just 1 ladder, more testing to follow.
Be careful! I'm at 28.2 of Varget in a 6 Grendel case at 2660 and feel like I'm near max. Case fill looked perfect. I do get very light ejector marks in my ill timed 18" 243 LBC. Hodgdon has 30.2 max Varget in the larger (10%+) 6mm BR case for 90s in the high 2800s out of a 24". Bolt gun pressures.
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Point well taken.
I used the hornady 87 gr Vmax data, which has 29.7 Varget, 2750 as listed max. So my 2858 is in line with this, for my faxon barrel which shoots ~100 ft/s faster than the gas gun 18" data.
But I'm not sure I'll use the Varget with this load. may still stick with 2520 or Lever.
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That's bizarre. Hornady's 87 data is a lot closer to their 80 data then their 90 for powders presented for all 3. I guess those GMX's have above average bearing surface while the 87 Vmax is below.
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10-26-2020, 09:56 PM
(This post was last modified: 10-27-2020, 12:36 AM by grayfox.)
Gmx is also a mono. They are lots harder to squeeze into a grooved barrel and so pressures spike lots faster.
I figured a 3 gr delta is not much in terms of wt differential, plus with a long tip the 90 ought to be like you said, close in terms of bearing surface.
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Ahhhh, I never realized the GMX was a mono. Which is cool - I can expect more from the Speer 80s in my 7.62x39 brass FrankenAmmo.
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Hey guys!
Sorry about jumping into a older thread, but it has the beginnings of what I am looking for and didn't want to clog up the forum with another thread.
As you can tell, I'm new to this forum, and consider myself pretty new to reloading. (I started learning how to reload late 2020.) I've done several good loads for 6.5 Creedmoor, and would like to look into doing my first 6mm ARC loads. I've shot enough of Hornady's Precision Hunter, Black, and mostly Match to have some brass to work with.
Given I have more that I can shoot to generate more brass, but thought I'd see about pulling the bullet and powder and saving the brass and primer to use for my initial development.
Any ideas as to what primers is being used in Match, Precision Hunter and Black? IIRC, I've seen both chrome and brass colored primers, so I'm even concerned if they are consistent in what they are using. I have some CFE223 on the way and have lots of LEVERevolution to work with for this cartridge.
Is this a dumb idea?
Thanks in advance!
-Dave
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Welcome aboard Dave. Hornady has always been inconsistent with their primers and uses whatever they can get their hands on. This predates the current environment. In the current environment, I'd guess that they are using foreign primers. I can't see how Vista or Winchester could be selling them primers in the current market when they can't make enough ammo themselves.
I would just shoot the factory ammo. Load development in virgin cases will not give you repeatable results when you switch to fired brass since the volume of a virgin case will be below the volume of a sized fired case. It may also result in different neck tension unless you run the brass through your die with the decap pin removed. But then you run into the issue of how to remove the lube on the inside of the neck with a primer in there......
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07-01-2021, 09:37 PM
(This post was last modified: 07-01-2021, 09:37 PM by daverx7.)
(07-01-2021, 07:57 PM)StoneHendge Wrote: Welcome aboard Dave. Hornady has always been inconsistent with their primers and uses whatever they can get their hands on. This predates the current environment. In the current environment, I'd guess that they are using foreign primers. I can't see how Vista or Winchester could be selling them primers in the current market when they can't make enough ammo themselves.
I would just shoot the factory ammo. Load development in virgin cases will not give you repeatable results when you switch to fired brass since the volume of a virgin case will be below the volume of a sized fired case. It may also result in different neck tension unless you run the brass through your die with the decap pin removed. But then you run into the issue of how to remove the lube on the inside of the neck with a primer in there......
Thanks for the welcome and quick reply, StoneHendge! It is good to know that my observation and memory of their primers wasn't off. What was surprising with the different primers within the same lot.
I appreciate the recommendation and reasoning for just shooting the factory ammo. I'll allow myself to be okay with them being good enough to ring a small gong at 300 yards... which it does quite nicely, and then do my development.
I look forward to learning with/from you guys with this very interesting cartridge... Now on to digging through the forums on the possibility of converting one of my SA Savage Mod 10's to 6ARC.
Thanks again!
-Dave
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Agreed, I have used 3 boxes of 6 arc black and all 3 shot like ?
ironically though I reloaded the brass with 95g Nosler B.T.'s and 28.5g of CFE and they shot great ? lol
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07-03-2022, 04:05 PM
(This post was last modified: 07-03-2022, 04:05 PM by gorillamotors.)
(10-26-2020, 01:13 AM)6mmAR Wrote: So I got in some of Horandy's factory "Black" 6mm ARC ammo (105 gr BTHP) and their "Match" 6mm ARC ammo (108 gr ELD) and after a go over of it before starting actual range testing (i.e. shooting them), all I am going to say is Hmmmm!
The "Black" ammo is loaded at right around 2.200" OAL which gives the bullet a jump of just about .040" to the lands on a SAAMI 6mm ARC chamber (at least the one I have).
The "Match" ammo is loaded right around 2.250" OAL which also gives the bullet a jump of just about .040" to the lands on the SAAMI 6mm ARC chamber (at least the one I have).
I pulled down a number of cartridges to measure the powder loads and just to see what was going on inside and here's what I found:
Both the "Black" and the "Match" are loaded with a ball powder that looks like a dead ringer for Hodgdon's CFE223 and the loadings also bespeak of a powder of a similar burn rate. In addition, the loads of both are under heavy compression. To get the powder out of the cases after pulling the bullets, I had to hold each case horizontally over a metal cup and insert a wooden toothpick in the case as I spun it to break up the solid chunk of powder in the case caused by the compression. Even then, the powder came out with clumps of the powder stuck together from compression. IMO - not exactly the recipe for accurate loadings (i.e. ball powder under heavy compression).
The loading of the "Black" varied from 30.12 gr to 30.38 gr..
The loadings of the "Match" varied from 30.58 gr to 30.60 gr..
Robert
I just picked up one box of Hornady's Black and one box of Hornady's Precision Hunter 6 ARC bullets on 1 July 2022. Did a comparison like you but not as in depth as you.
The 'Black' was loaded with 27.12 to 27.31 gn (using only 5 bullets) of powder. COAL was 2.206"
The 'Precision Hunter' was loaded with 24.96 to 25.18 gn (using only 5 bullets) of powder. COAL was 2.255"
All loads were heavily compressed as I had to use a toothpick to remove the powders.
I used my microscope to look at the powders of each including CFE223 and Leverevolution. LVR and CFE223 look similar under the microscope there were a few subtle differences. The powders in both bullets seem to resemble CFE223. Although that is not a definitive answer it gives me a starting point.
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