6mm ARC - Practical Reloading

[Lkwebb]

Got everything to put a 6 ARC AR together except for the barrel. Probably have about a 3 month wait for that from CLE. My smith had a couple pounds of H380 stashed away so I picked that up yesterday. That's my slowest burning powder since all I've been shooting so far are lighter bullets up to 80 grains. The H380 is right below Leverevolution on the burn charts so hopefully it will work OK for 105-108 grainers.

I might just pick up a Ballistic Advantage barrel while waiting for the CLE barrel. 3 months is a long wait............

Check out my buddy kenny at www.dpgunworks.com. he is doing 6mm arc barrels

 

[Lkwebb]

Check out my buddy kenny at www.dpgunworks.com. he is doing 6mm arc barrels

He is also on YouTube under eagle eye shooting...

 

[gjcamacho]

Wanted to learn about what others are trying and share my experience so far:


Build:

• 20” 1:7 twist 416 SS DMR Profile Ballistic Advantage barrel
• Vltor upper and lower
• Ballistic Advantage bolt in PSA premium bolt carrier
• Adjustable gas block
• TBAC Ultra-9 suppressor
• Geissele SSA-E trigger

Goal:
It would be fun to have a relatively light weight AR-15 platformed rifle that can consistently shoot at or under .5 MOA from 100 to 1000 yards.

Testing:
From prone using Joy-Pod bipod, Bigfoot rear bag and NF 5.5-22X50 optic. All rounds loaded to 2.26 COAL.

First steps:
Using the lathe, I modified some 6.5 Grendel dies by shaving off .040 from the base and replacing the neck sizing bushing. I set the dies up in a Forster Coax press and using annealed 6.5 Grendel brass, sized the necks down and pushed the shoulders back to the SAAMI specs. I also used a Sinclair carbide expander mandrel before loading.

First firing:
I was lazy, and using known data from the 6mm AR, I loaded 27.5 grains of H4895 under a 105 Berger Hybrid Target. This was way over pressure yielding speeds in the 2730 FPS range, heavy ejector swipes and unusably expanded primer pockets. Groups were all in the 1 to 1.5 MOA range at 100 yards. SDs were in the low single digits, however! Bad test - bad approach and dangerous. I know better and am lucky to re-learn that lesson without the pain that often accompanies such learnings.

Second firing:
Testing from 26.0 grains of H4895 up to 26.5 grains showed better results. The best results were the 26.5 grain charges with speeds of 2594 but SDs in the 17 FPS range. 100 yard groups were in the mid .5 MOA range. The groups got worse as the the powder charge decreased. No pressure signs, swipes or ejector marks at this charge range. It is, however, over pressure according to Quickload.

Changing gears:
I received some Hornady 105 grain Black factory ammunition that shot poorly in my barrel. Speed was good at 2640 FPS and SDs were a reasonable 11.4 FPS. Group sizes at 100 yards were terrible at 1.9 MOA.

I also tried some VARGET under the Hornady 108 ELD-M. 27 grains yielded 2554 FPS with a 5.5 SD and very repeatable .5 - .52 MOA at 100. I took these out to 700 and 900 yards on a windless day with the same .4 to .5 MOA results. The lack of wind is unusual but was welcomed. There were no pressure signs at this charge weight, however, Quickload estimates that this is 3900 PSI over SAAMI pressure.

Learning so far:
Fired by not resized converted 6.5 Grendel brass holds 34.74 grains of water and fired but not resized factory 6mm ARC cases holds 34.58 grains of water. In Quickload I edited a 6 PPC case for case length and case capacity and now get estimated MV within 2-4 FPS of what I have measured using the Labradar.

Disclaimer:
All of the above hand loads are above 52000 PSI, and, as such, I am obligated to warn everyone from trying them. If you do so, you are doing it at your own risk.

Next Steps:
It looks like the 27 grain VARGET and 108 ELD-M combo is very close to a predicted OBT node. .2 to .3 more grains is what I am going to test next.

Additionally, I don’t want to give up on H4895. I want to test this powder with both the 108 ELD-M and the 105 Hybrid Target.

• Will try 26.6 H4895 with 108 ELD-M expecting 2608 FPS out of my barrel.
• Will also try 26.5 H4895 with 105 Hybrid Target expecting 2635 FPS out of my barrel.

Both of the above correspond to OBT nodes using Quickload.

Request:
There is already a big thread in progress discussing the merits of this cartridge which is interesting but not the intent of this one. Would like to keep this thread focused on practical experience and suggestions to optimize safe hand loads for this cartridge in semi-auto gas rifles.

Hope this helps someone,

Henryrifle

Shame this thread died... its 2022 and the 6ARC is still chugging along.

 

[Retired shooter]

Hello to all that are still participating in this thread. I have a upper being built chambered in 6 ARC. Was going with 223 Valkrie till I got persuaded to try 6 ARC. From all the previous posts it looks like CFE 223 and Leverevolution have been the successful powders. I will be trying the 109 bergers first, looking to shoot past 1500 yards maybe a mile shot on steel. Has anyone tried AR comp powder, wondering how that has worked.

Anyone have a honey spot located to purchase brass..?

Thank you to all that have shared information and wisdom gained on the 6 ARC.
Looking forward to learning more about it.

 

[Bamban]

Harvested a 20 inch 6 ARC from a 6 BRA PRS take off barrel. Buddy gave me 3. The 6 ARC sports the same contour as our AR15 competition service rifles.

Here is a picture for comparison how a donor barrel looks like. The 6 ARC is going to a young lady in AZ.

 

[Retired shooter]

Very nice, the barrel, as well as your lathe.

 

[David Milisock]

Hello to all that are still participating in this thread. I have a upper being built chambered in 6 ARC. Was going with 223 Valkrie till I got persuaded to try 6 ARC. From all the previous posts it looks like CFE 223 and Leverevolution have been the successful powders. I will be trying the 109 bergers first, looking to shoot past 1500 yards maybe a mile shot on steel. Has anyone tried AR comp powder, wondering how that has worked.

Anyone have a honey spot located to purchase brass..?

Thank you to all that have shared information and wisdom gained on the 6 ARC.
Looking forward to learning more about it.

I've just been buying factory ammo in lots to get brass. I've also been doing loads of research on rifle builds and loads. I'm looking for a different outcome than you but the parameters, seem the same.

It appears that to a high degree that due to the bolt thrust being near the upper parameter, that rifle builds need to stay to a strict structure and powder for 105+ grain weight projectiles limited almost exclusively to LeverEvolution or very close to that burn rate.

 

[Retired shooter]

Have picked up factory loads just for the brass, have also received some 6.5 grendel to resize, have Forster dies to work with.

Upper assy being built to go the longer distance and gas block set to slow down the bolt, also better bolt carrier group being used. So far just gathering all the parts and pieces, but thinking about what powder to use, also looking for the not readily available bullets.

Only load data I have is from Berger that is not in published form just yet, and the reload manuals.
Obviously looking for velocity first.

Thank you.

 

[Retired shooter]

Hello all
From those of you that have loading experience with the 6ARC using Leverevolution , are you finding that to be a compressed load. The load data I received from the Berger rep. shows that to be 102% case fill.( have never been one to push pressure issues, and will be more cautious with the 6 ARC)

Also some here saying the 107 Sierras are performing well. In your opinions, better than the 109, or the 115 Bergers. Strictly longer range shooting

I am late to the 6 ARC party, and do not have the upper assy , still trying to find heavier bullets, just gathering supplies, equipment, and looking for some experienced info.

Thank you to all.!

 

[gunsandgunsmithing]

Hello all
From those of you that have loading experience with the 6ARC using Leverevolution , are you finding that to be a compressed load. The load data I received from the Berger rep. shows that to be 102% case fill.( have never been one to push pressure issues, and will be more cautious with the 6 ARC)

Also some here saying the 107 Sierras are performing well. In your opinions, better than the 109, or the 115 Bergers. Strictly longer range shooting

I am late to the 6 ARC party, and do not have the upper assy , still trying to find heavier bullets, just gathering supplies, equipment, and looking for some experienced info.

Thank you to all.!

If it were me, I'd run the numbers of say 90-95 bergers vs the heavies. The ARC and Grendel lack the capacity to utilize the really heavy for caliber bullets, imho. Just run the numbers along with respective velocities for both and decide for yourself.

 

[Retired shooter]

Thank you .!
Have looked at the various bullet BC, the Bergers appear to be the best. I know what I will be trying will be difficult, however due to long range elevation drop and wind, I will try the heavier pills first. Have just ordered from Powder valley some 115 grainers to get started with.

Have Cfe 223 powder to start with, was wondering about the Leverevolution, from those who have already been there done that.

Thank you.!

 

[SD guy]

Seems my use varies a fair bit from most here. 6mm ARC came in to my stable via CZ527 in 7.62 x39 re-barreled to 6.5 Grendel & more recently to a Pacnor 6mm 22" 7.5 twist 5 land chambered in 6mm ARC light taper barrel for deer hunting & more. Loaded lots of Cup & core bullets as well as a few lead free options in the last 18 months or so. First year hunting load turned out to be the 108 grain Elite hunter over 29.4 Grains of Leverevolution propellant. Worked exceptional with a 254 yard high shoulder shot.

This years rifle season is coming to a close this weekend Load for this season was the 87 grain Absolute hammer over a fairly stout load of IMR 8208. Thus far the rifle has taken 2 does No complaints here thus far.

Just ordered some surplus Powder that is supposed to be the same or similar to Power Pro 2000 MR propellant. Any one care to share thoughts on power pro 2000 MR in the 6mm ARC? Suppose I am hoping for insight along the lines of bullet weight considerations, primer selection & temp stability.

 

[SpikeDiesel]

If it were me, I'd run the numbers of say 90-95 bergers vs the heavies. The ARC and Grendel lack the capacity to utilize the really heavy for caliber bullets, imho. Just run the numbers along with respective velocities for both and decide for yourself.

This! I run 95gr Berger VLDs over Leverevolution in a bolt action and tested to a little over 3000fps without pressure. I settled on a load right around 2950fps which gives me 9.1mils to 1000yds, this mirrors my 140gn 6.5 Creed load.

Rifle is a Zermatt Origin action with a 26” Proof competition contour.

 

[Raptor]

Hello to all that are still participating in this thread. I have a upper being built chambered in 6 ARC. Was going with 223 Valkrie till I got persuaded to try 6 ARC. From all the previous posts it looks like CFE 223 and Leverevolution have been the successful powders. I will be trying the 109 bergers first, looking to shoot past 1500 yards maybe a mile shot on steel. Has anyone tried AR comp powder, wondering how that has worked.

Anyone have a honey spot located to purchase brass..?

Thank you to all that have shared information and wisdom gained on the 6 ARC.
Looking forward to learning more about it.

I assume you are building a bolt gun and not an AR to try and shoot those ranges. I don't know why you are going with an ARC if you want to shoot those distances. I honestly think you would be better served with one of the other HP 6MM rounds if you're building a bolt rifle. If you ARE building an AR I honestly think you will be disappointed in the results at those ranges.....

 

[SD guy]

Think you are really stretching the legs of the 6mm ARC at 1000 yards much less 1500 yards. Personally I like this round in a mini bolt action rifle. though I do not expect to go much past 300 yards for my use.

 

[Retired shooter]

Yip it is an AR. Way I look at it the lower half of the AR just serves as a way to hold on to the upper half.
Had the lower, having a upper built to attempt the longer stuff. Always enjoyed a challenge. We shall see what happens

 

[Retired shooter]

Yip it is an AR. Way I look at it the lower half of the AR just serves as a way to hold on to the upper half.
Had the lower, having a upper built to attempt the longer stuff. Always enjoyed a challenge. We shall see what happens

My son has started ELD , or ELR shooting, the range we go to is about 2 hr drive for me. I know they can shoot at least 2 miles at that range. He is shooting a .338 Lapua on a Savage rifle, and has rang the steel ( 2 ft. X 3 ft.) at one mile our first day there. My main job is spotting for him. I am retired, so cash pot is not overflowing. If we are lucky we will make the trip to the long range twice, maybe three times a yr.

The range where I am a member is a 600 yard . So that will be my most commonly used range. I am having the upper built for longer distances, shooting steel targets only. I no longer hunt, and while I admire the guys putting 2 bullets thru one hole, it's not for me. Do not shoot any competition, all of mine is for the fun.

Putting the new upper on with a slightly larger bullet ( meaning slightly less expense for reloading)
made more sense than a complete new rifle. Yes I know the bolt action is better, however a lot of the cash flow has gone to equipment needed to help my son.

So for you wondering why I am doing what I am there is my reasoning, The 6 ARC caught my attention, I researched it a little, and decided to try it. Will be the last firearm I purchase, and the only custom piece of firearm I have had.

Long story, tired of typing and trying to catch what auto correct tires to imput.

 

[Gtscotty]

I finally got a chance to Chrono a few each of some of the loads I've worked up for my lightweight 18" hunting 6mm ARC:

95gr SST, 29.5gr LVR, 2.1" - 2,676 fps, 2,680 fps
100gr TGK, 29.3gr LVR, 2.27" - 2,676 fps, 2,665 fps
108gr ELD, 29.3gr LVR, 2.245" - 2,650 fps, 2,634 fps

Also worked on a load for 90gr TGKs, and chrono'd this spread:

90gr TGK, LVR, 2.265
30.4gr - 2,802 fps
30.7gr - 2,834 fps
31gr - 2,874 fps
31.3gr - 2,935 fps

I'm happy with all the previously developed loads, and the 18" isn't turning out to be much slower than my 21". I'll probably take the 100gr or 108gr loads (they group together) into the woods for deer this year. Here's a picture of the rifle, it has a lightweight X-Caliber barrel, not pricey but I'm very happy with how it turned out as a hunting carbine.

 

[Retired shooter]

I finally got a chance to Chrono a few each of some of the loads I've worked up for my lightweight 18" hunting 6mm ARC:

95gr SST, 29.5gr LVR, 2.1" - 2,676 fps, 2,680 fps
100gr TGK, 29.3gr LVR, 2.27" - 2,676 fps, 2,665 fps
108gr ELD, 29.3gr LVR, 2.245" - 2,650 fps, 2,634 fps

Also worked on a load for 90gr TGKs, and chrono'd this spread:

90gr TGK, LVR, 2.265
30.4gr - 2,802 fps
30.7gr - 2,834 fps
31gr - 2,874 fps
31.3gr - 2,935 fps

I'm happy with all the previously developed loads, and the 18" isn't turning out to be much slower than my 21". I'll probably take the 100gr or 108gr loads (they group together) into the woods for deer this year. Here's a picture of the rifle, it has a lightweight X-Caliber barrel, not pricey but I'm very happy with how it turned out as a hunting carbine.

View attachment 1390952

Scotty
Thank you for posting your chrono results with Lvr.
I have CFE 223, and did not get LVR ordered from P V quick enough this week. I have looked back thru the older posts for powder info, yours is first I have seen for Lvr. Have you chrono any of the Cfe 223 .
If so how do they compare,.

Thank you.

 

[Gtscotty]

Scotty
Thank you for posting your chrono results with Lvr.
I have CFE 223, and did not get LVR ordered from P V quick enough this week. I have looked back thru the older posts for powder info, yours is first I have seen for Lvr. Have you chrono any of the Cfe 223 .
If so how do they compare,.

Thank you.

I haven't used CFE 223 in 6 ARC, from what I've read though, it is very similar to LVR. The published Hornady data shows similar velocities between CFE 223 and LVR, with charge weights on CFE being a little lower. While it seems like most folks are loading LVR in the 6 ARC, CFE 223 and AA2520 also have a strong showing.

It looks like Hodgdon just put a few new powders in the Staball line on their website, Staball Match and Staball HD. Fingers crossed, but the Match variant looks to be in the Varget-LVR speed range, might be perfect for the ARC.

Winchester StaBALL Match

Winchester® StaBALL™ Match is a temperature-insensitive, double-base, BALL® Powder, stable in extreme-hot or -cold conditions. This powder provides optimal loading density in cartridges appropriate for the burn speed, which is ideal for high-BC heavy for caliber bullets in 223 Remington, 224...

shop.hodgdon.com

If you're looking for more robust discussion on 6 ARC including loads, there is a long thread on the Hide worth checking out.

New 6mm Advanced Rifle Cartridge

I've kind of got my hopes up for this one. Agreed; I noticed there are a few different StaBall-family powders in the works and have been keeping an eye out for them. It'll be interesting to see how they do. I honestly have not had good results with 6.5 StaBall in my Creedmoor (I have to go...

www.snipershide.com