New 6mm Advanced Rifle Cartridge

Yondering

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Found new Starline Grendel brass in stock - 1k ordered. will post when they are actually on the way/arrived. They have 6.5CM in stock right now too.

On to waiting for primers and looking for more bullets.

Thanks for the link, just ordered more myself.
Starline seems to handle pressure better than Lapua in this cartridge, and uniformity seems to be nearly as good. I neck turn all my 6mm brass and both of these brands only need a couple thousandths taken off at most.
 

Yondering

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Has QL come out with a 6 ARC program yet? I know most folks are using a modified Grendel program, and I have yet to see accurate data from the modified Grendel program.

I agree; IMO I’ve yet to see any QL data posted for this cartridge that’s of any real value, and it doesn’t even seem to do a good job of predicting the best powders compared to published load data or my own experience.
 

MichiganMitten

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Found new Starline Grendel brass in stock - 1k ordered. will post when they are actually on the way/arrived. They have 6.5CM in stock right now too.

On to waiting for primers and looking for more bullets.
The brass to order for reloading is the "Starline 6.5 Grendel Brass"? Why 1k instead of 500? Would you ever use more than 500 at a time? I'm just getting into reloading, and am trying to figure out best practices.
 

Yondering

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The brass to order for reloading is the "Starline 6.5 Grendel Brass"? Why 1k instead of 500? Would you ever use more than 500 at a time? I'm just getting into reloading, and am trying to figure out best practices.
Seems like a lot of people are buying large quantities just because there’s a shortage. Which of course drives more shortages. But other guys actually use it, especially the prairie dog shooters although I can’t speak for anyone here on that.

Personally, 1K pieces of something like 9mm brass isn’t nearly enough but in this cartridge I’d probably never use it all. With this recent order I’ll have 500 pieces of Starline, and my only reason for that much is that I use it in both 6.5 and 6mm so it’s just 250 for each. I have loaded some of this up to 12 times now, and when sized with proper shoulder bump it’s still working like new, so it lasts a long time.
 
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SWFShooter

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I agree; IMO I’ve yet to see any QL data posted for this cartridge that’s of any real value, and it doesn’t even seem to do a good job of predicting the best powders compared to published load data or my own experience.
I will assume both of you are skilled reloaders and aware of the functions of Quickload, so keep in mind building a case is one of the easier non-standard functions, especially for a 6mm ARC, which is a cross between a 6mm AR/6mm Grendel and a 6PPC will the neck shortened, so case creation is easier if you don't have to start from scratch. (unlike all these Sherman wildcats I am getting requests for when I don't even know what the parent case is until I research...SS, SST, SM, Max, Mega, what the hell - for the record, the Shermans are some pretty good cartridges seemingly well designed). New bullet creation in QL is a bit more work, except Berger bullets as they provide most of the required information on their new products, as long as you are copying a similar product already in QL. As far as powders, of course you know that many powder companies, especially St. Marks, do not release properties of all of their powders, so some of the powders are not available. You could try to guess at the parameters, but it rarely will be accurate, so people just have to go old school with those. Then there are a few powders that need to be updated, as the source has changed, such as some of what were Accurate powders are now marketed Shooters World powders (Lovex). The one Quickload function that you should consider trying is "all powders" where you do a what-if of a case, bullet, etc., and then run the all powders analysis and based on selected parameters, you can start to weed out poor options for that specific case based on case fill, % burn, velocity, etc., etc. You still have to determine if the powder parameters supplied to QL are accurate, and the actual results can be affected by the case geometry. For the 6mm ARC, it seems that after George Gardner stated early on that Leverrevolution was a good option, people locked in on it. And of course, LVR is basically a bulkier version of CFE223, and both are somewhat similar to 2000MR. 2000MR is not released to QL, so you have to go old school with it. And CFE223 has proven better with lighter bullets, and about equal to LVR with heavies, if you like working with ball powders. As far as perfect powders, I prefer to use temp stable optionss, the velocity of a ball powder isn't there, but consistency is more important to me personally. Quickload is just one tool, equal importance as a chrono, good brass prep, or a good method of weighing powder or seating a bullet, or many other steps. Except Quickload requires a lot more verification of inputs and analysis of actual field results. Many of the people I know who have bought Quickload program were frustrated with it an gave up trying to figure out how to apply it to their load development. It doesn't tell you the exact load, but rather basically shows you where to look for it. Now back to your regularly scheduled 6mm ARC discussions. :)
 

Yondering

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And of course, LVR is basically a bulkier version of CFE223.....

. And CFE223 has proven ... about equal to LVR with heavies,

No, and no. Yet another example of your relying too much on what QL says and making assumptions from it.

And that’s the problem right there. People like you think that the data QL gives you is good data, without understanding some of the assumptions that go into it. Same as with your optimum barrel time assumptions.
 

SWFShooter

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No, and no. Yet another example of your relying too much on what QL says and making assumptions from it.

And that’s the problem right there. People like you think that the data QL gives you is good data, without understanding some of the assumptions that go into it. Same as with your optimum barrel time assumptions.
That is actual field tests, apparently your results differ. With your people like me comment, I guess we are done here. Have a good one.
 

Dogtown

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1620933689626.png

I just got the latest QL Data Update - it's in there now
 
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newageroman

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The brass to order for reloading is the "Starline 6.5 Grendel Brass"? Why 1k instead of 500? Would you ever use more than 500 at a time? I'm just getting into reloading, and am trying to figure out best practices.
I've shot and converted this brass before. It works great for me. I'm basically dumping 223 loading for this round. I have local friends that load this round. Starline has this on backorder. I think it's gonna be the new 6.5 CM for the AR-15 so demand will be there.
 
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fifdynutz

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i recieved my arm or ally brass yesterday and it converted perfectly. ive always had great luck with arm or ally with ship times.

I also worked on some of my load development with my faxon 14.5" 6arc setup i use to night hunt. Ive been shooting the hornady black 105's all season with great luck. I chose the load on these that best matched the factory ammo (that shot great in this barrel) and loaded them to be super reliable, and are surprisingly pretty fur friendly. They have proven flat enough i can aim on fur out to 300 "ish" with a 50yd zero

Currently building a 16" setup so i can compare speeds with the same loads and help contribute to some barrel length calculations.

here is the data i landed on so far for 103g ELDX and 90g ELDX. I tried both varget and CFE with CFE providing much higher velocities. i may load a few boxes of varget just for the below zero nights we may be hunting.

1x hornady case
14.5" faxon heavy profile
mid length gas-unsuppressed
CCI BR4
1.70 O-Give (matches factory hornady black)
stone cold reliable piece in all weather conditions so far

VARGET 90g ELD-X
27.8-2450
28.0-2465 - best SD
28.2-2496

VARGET 103g ELD-X
26.0-2260
26.2-2300

CFE 90g ELD-X
30.0-2663
30.2-2700 - best SD
30.4-2710

CFE 103g ELD-X
26.8-2290
27.0-2320
 

fifdynutz

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I was focusing on the 90's for those tests and am pretty happy with how the 2700fps loads shoot. Going to work up some hotter 103s for distance shooting when I finish the 16" gun
 
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Yondering

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I was focusing on the 90's for those tests and am pretty happy with how the 2700fps loads shoot. Going to work up some hotter 103s for distance shooting when I finish the 16" gun
Just a tip - the 90gr TGK is a little different profile than the ELDX and can be pushed another 100 fps faster from my 19” barrel (maybe ~80 fps faster from your 14.5”?). It can be seated farther out without getting into the lands, providing more powder capacity, and the shorter bearing surface contributes as well.

The guy who got me interested in these two bullets said he had poor results on coyotes with the TGK but also said the ELDX wasn’t any better. I haven’t used them on meat or fur yet, just long distance steel and they work great for that.
 

fifdynutz

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i'll definitely snag some of those once i see some available. these heavier bullets at these speeds seem to be slamming dogs no matter what as long as shot placement is decent. I think the 105g BTHP i used most of the winter had a lot of pass thru's but it was very difficult to find a hole
 

newageroman

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Shot 1k groups yesterday. The Valdada fixed made it possible/easy. Once I got dialed in at 600 I just used holds and no dialing!!!
Shot my sporter Eddystone and the CZ pistols too, it was a great day. The glass on this thing lets you see hits at 1k then listen for the ding.
At the end of the day I annealed 427 pieces of brass and I have 1k more on the way - again, goodbye 223...
 

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Kpchurch

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Starting a 6ARC build, my first AR build. I’ve received the upper, lower (SLR), trigger (TT), stock (PRS Gen 3), charging handle (Radian Raptor SD-SL), and other various small parts. I did just get in my 6ARC die (SAC).

I compared the .265 bushing in SAC 6ARC die vs. the standard .265 bushing in the attached photos.

I’ve really been looking for either Lapua or Starline 6.5 Grendel brass. Maybe June will be my lucky month.

Still needing to place an order for my barrel and hand guard. Can’t decide if mine going with a 24” or an 18”? I will be using a TB Ultra 9 in 6.5 can with it. Mainly for LR shooting and possibly try it out in a 1-day PRS.

I wish I could find a hand guard with in a built in Arca rail. Otherwise I’ll need to get an Area 419 Arca to add on too.

Any recommendations on hand guards or barrels? Leaning towards a Bartlein in their 400 material.
E01C679D-3121-437B-80B9-2218911D7223.jpeg
97A32321-742B-45F0-B1BA-B5AAC7A6DA40.jpeg
 

7mmShooter

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Starting a 6ARC build, my first AR build. I’ve received the upper, lower (SLR), trigger (TT), stock (PRS Gen 3), charging handle (Radian Raptor SD-SL), and other various small parts. I did just get in my 6ARC die (SAC).

I compared the .265 bushing in SAC 6ARC die vs. the standard .265 bushing in the attached photos.

I’ve really been looking for either Lapua or Starline 6.5 Grendel brass. Maybe June will be my lucky month.

Still needing to place an order for my barrel and hand guard. Can’t decide if mine going with a 24” or an 18”? I will be using a TB Ultra 9 in 6.5 can with it. Mainly for LR shooting and possibly try it out in a 1-day PRS.

I wish I could find a hand guard with in a built in Arca rail. Otherwise I’ll need to get an Area 419 Arca to add on too.

Any recommendations on hand guards or barrels? Leaning towards a Bartlein in their 400 material.
View attachment 7632245
View attachment 7632246
Catalyst Arms has an Arca handguard, Geissele makes one as well if I'm not mistaken
 

skyrep

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Starting a 6ARC build, my first AR build. I’ve received the upper, lower (SLR), trigger (TT), stock (PRS Gen 3), charging handle (Radian Raptor SD-SL), and other various small parts. I did just get in my 6ARC die (SAC).

I compared the .265 bushing in SAC 6ARC die vs. the standard .265 bushing in the attached photos.

I’ve really been looking for either Lapua or Starline 6.5 Grendel brass. Maybe June will be my lucky month.

Still needing to place an order for my barrel and hand guard. Can’t decide if mine going with a 24” or an 18”? I will be using a TB Ultra 9 in 6.5 can with it. Mainly for LR shooting and possibly try it out in a 1-day PRS.

I wish I could find a hand guard with in a built in Arca rail. Otherwise I’ll need to get an Area 419 Arca to add on too.

Any recommendations on hand guards or barrels? Leaning towards a Bartlein in their 400 material.
View attachment 7632245
View attachment 7632246
Sgt. of Arms have the ARCA Handguards on hand: https://www.sgtofarms.com/product-page/sgt-of-arms-ar-15-17-5-arca-handguard
 

newageroman

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Shot my first 600 match yesterday. I was last against a stack of bolt guns that cost more than my daily driver. This weekend is a timed 100-1000 match that would be a great match for the rifle (all holds no dialing), but I'll most likely be teaching the 6 yr old how to shoot 22 for the first time so priorities...
I did convert another 500 Grendle cases between rounds and finished fire forming the others I had made. With the jammed fireforms at 2500 I was able to hit the 4" swingers and 6" swingers at 500 yds after the match. Rifle and bolt getting a deep cleaning now.
Shipping all my old 223 brass out today! gooooooodbye!!!!
 
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LRBuck

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Sep 25, 2020
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Starting a 6ARC build, my first AR build. I’ve received the upper, lower (SLR), trigger (TT), stock (PRS Gen 3), charging handle (Radian Raptor SD-SL), and other various small parts. I did just get in my 6ARC die (SAC).

I compared the .265 bushing in SAC 6ARC die vs. the standard .265 bushing in the attached photos.

I’ve really been looking for either Lapua or Starline 6.5 Grendel brass. Maybe June will be my lucky month.

Still needing to place an order for my barrel and hand guard. Can’t decide if mine going with a 24” or an 18”? I will be using a TB Ultra 9 in 6.5 can with it. Mainly for LR shooting and possibly try it out in a 1-day PRS.

I wish I could find a hand guard with in a built in Arca rail. Otherwise I’ll need to get an Area 419 Arca to add on too.

Any recommendations on hand guards or barrels? Leaning towards a Bartlein in their 400 material.
SView attachment 7632245N
View attachment 7632246
Sounds like you are off to a great build.

I am very very happy with my Rock Creek 22”. If I do my job I get .4-.5 moa consistently.
Can’t go wrong with Bartlein either IMO. I will probably go that route with my next one for the cut rifling. Paul Craddock told me the barrel life in the 6mm ARC is about 40% more with the cut rifling over button. I decided on the RC for costs because at the time I wasn't sure (after my 224 Valkyrie experience) about the 6mm ARC - I am now. Love it.
As to length, others seem to be happy with their 18”. I reach the 1200 plate with my 22” in hand-loads (109g Berger). Haven’t tried that far with the factory 108 ELD’s. I don’t shoot suppressed.
If you are going past 1000, probably will want the extra inches.
Good Luck!
 
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newageroman

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So... I got bored today and cleaned the bolt and pulled the extractor and ejector. It was pretty dirty, but the Lucas Bore cleaner worked great! Disassembled the bolt and removed the extractor and ejector.

Confirmed easy lockup with bolt you could see/feel the lugs move easily. My first time doing this with a dis-assembled bolt in an AR. So please confirm/correct my test before I go and trim all my new cases.

Dropped a freshly converted brass (NEW Starline Grendel sized to 6ARC BUT no trimming yet len is 1.515”) down the bore and tried to chamber and it would not lockup (as expected).

SAMMI Spec is 1.490” so betting it is somewhere in between.
  • 1.513” will NOT lockup
  • 1.5105” will lockup.
  • 1.508” will lockup- fairly easily.
Soo… a little bit of work leads to a trim length that is WAY longer than 1.488”. That’s 20 thou longer than what I have been trimming to. Is there any advantage of leaving the trim long? Less brass growth is what I’m thinking, but there may be cons as well, like if one is just a hair too long it won’t chamber for example. Is it better to just stay short? How short?

I'm leaning toward 1.508" as a new Max trim for this chamber. What are the chances this will affect my group size or velocity? I'm thinking changes will be minimal but will run a test batch this weekend to make sure.

Thx to whoever suggested/mentioned this test - I think it was in relation to shoulder bump/chambering, but trim len seems to be closely related/testable in this situation.
 

Ledzep

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  • Jun 9, 2009
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    If brass grows and interferes with the front of the chamber you're basically turning the Barrel into a taper crimp die while also removing necessary clearance. You'll spike pressure and velocity pretty bad. I usually have .010 minimum from the front of the chamber for trim clearance.
     
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    newageroman

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    Yes, I do remember this from early reloading days of 30-06. TY for that reminder. I was thinking more in terms of more neck tension but that is a good point. In terms of brass growth, it seem to me that it comes more from bumping shoulder too much as opposed to trimming brass down too much. I don't want to stray off topic so I will just trim to 1.508" - 0.010" = 1.498" and call it there. Thx!
     

    fifdynutz

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    Got this one all finished up, going to do get the barrel broke in and see what this 16" does on the chrono vs my 14.5
     

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    CIB2007

    "Figure It Out“
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    Finally got my barrel from Paul craddock. He’s a great guy to do business with. So threw the build together and off the range to dial in the gas system. I’ve got too many projects going hence the mess.
     

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    Fret

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    Finally took the new 6ARC AR out to shoot some 5 shoot groups at 100 yards with different loads. Was going to take the PPC but it was too windy so took the AR instead. I think it shot OK. Used Leverevolution from 29 to 30.3 grains and 80 grain Bart's with 0.005 jump. No pressure signs so might go higher next time.

    UUVlxnlh.jpg


     
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    jbailey

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    Finally took the new 6ARC AR out to shoot some 5 shoot groups at 100 yards with different loads. Was going to take the PPC but it was too windy so took the AR instead. I think it shot OK. Used Leverevolution from 29 to 30.3 grains and 80 grain Bart's with 0.005 jump. No pressure signs so might go higher next time.

    Really nice shooting there.

    Question: 80 grain Bart's - could you give us the details on this bullet???

    thanks.
     

    Fret

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    Really nice shooting there.

    Question: 80 grain Bart's - could you give us the details on this bullet???

    thanks.
    Thanks. It's a boattail I usually shoot with my 6BR. I bought some 108 Bergers but the freeborn on this barrel seems too short for them so I loaded the 80s.

     
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    newageroman

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    More small piles, but with old powder.
    Also just scored 3# of LeverEvolution from precision reloading...
     

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    Ironman675

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    Paul Cradock is the Man, had to start off with that. finally after having this upper since last fall I got out and fired it today. Using factory Black ammo and spending the first ten rounds to zero and adjust the SLR gas block with the tranquilo, the following ten rounds proceeded to print a nice 1.14 group at 100m. I am not one of yawl's amazing shooters and this is the first 20 rnds. thru this barrel, I am stoked.

    for you tech folks
    Bartlien 5R 20
    craddock upper
    Aero lower
    Larue MB2 trigger and Tranquilo sup
    JP silent spring
     
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    LRBuck

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    Has anyone tried loading the 112 Barnes Match Burners in 6mm ARC yet?
    Bullet stock is getting low and I ordered some of em - can’t find much else. There is a thread on them and those posting (6 creed, BR etc) seemed to like them.
     
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