6 ARC load recommendations- 18” AR

[ReaperDriver]

Hi all. I did a search here by found very little info on 6 ARC load data. I’m just getting ready to dive into the loading process and any info would be much appreciated.

I built an AR w/ a PROOF 18” stainless. So far it shoots well out to 1k with factory Hornady 108 ELDM loads. My plan is to shoot Berger 105s HT and Hornady 108 ELDMs in Hornady Brass.

The main thing I’m looking for help with is which powder to use? I’ve got a fair amount of Varget and TAC. Are there any other suggestions? Any pet loads you want to share as well would be welcome.

Huge thanks in advance.

 

[FuhQ]

Try CFE223 or LeverEvolution. Those will be your 2 best powders for the 6 ARC.

Also, I got better groups and more consistent groups with regular CCI 400 primers, and NOT the magnum 450 primers.

 

[Dogtown]

Yup, LVR is especially well suited to 6ARC and weirdly it seems to get more consistent the harder you push it.

I actually just tested out RL17 w 105s today and got good results.

 

[supercorndogs]

Mine has shot well with Varget so far.

 

[newguy2k3v2]

It’s on the slow side at 2575ish but 28.5 cfe223 is scary accurate for me. 108 eldm at same oal a factory in converted Hornady grendel brass. 18” proof ss. I have a jug of lever but haven’t tested it yet

 

[db2000]

Any 59 gr VMAX and A2230 loads on here?

 

[Dogtown]

No personal experience, but QL predicts it would be a good fit.

 

[Jabberjaw]

Varget works well. Lever and cfe 223 are too temp sensitive, no brass as of yet. I have tried to form brass from 6.5 and it seems it loves to develop a belt. Hopefully someone will make better brass.

 

[TripleBull]

Varget works well. Lever and cfe 223 are too temp sensitive, no brass as of yet. I have tried to form brass from 6.5 and it seems it loves to develop a belt. Hopefully someone will make better brass.

I suspect you know Hornady makes 6 ARC brass and I just found out recently that Starline has 6 ARC brass - but I can't find any in stock.

I'm not a fan of Hornady brass but I've made it work by using the LE Wilson full length die with neck bushing (FLBD). I have not yet gone beyond 4 reloads on Hornady brass and have had good to excellent results thus far. I'm not seeing much movement in the Hornady brass and have not had to trim yet. Going forward, my plan is to reload Hornady brass for self-defense ammo and varmint hunting and to limit the number of reloads per case. When I eventually find Starline in stock, I'll buy a few hundred and have good expectations.

For longer range work, which is my primary excuse to play around with 6 ARC, I've been using Lapua 6.5 Grendel brass and am using two LE Wilson FLBDs to sequentially size the brass. I'm finding more consistent base-to-datum results and more consistent neck tension by sizing the Lapua brass in stages. So I do part of the shoulder setback and neck sizing with the first die, then anneal with an AMP, then finish with the second FLBD die, trim, run a mandrel, prime, charge, seat. I'm seeing about the same precision at 100 and 400 yards with Lapua brass and Hornady and for an AR, I'm happy with the results, which run in the 0.4 to 0.75 MOA range at 100 yards for an optimized load.

I'm mostly loading 109 Bergers but have also loaded the Hornady 108 ELDM and the 110 A-Tip. The Bergers are finicky on base-to-ogive, liking OALs beyond SAMMI for best performance. I run out where I'm magazine limited on OAL. I've only taken the ATip through the load optimization stage and it shot great, with a 0.5 MOA group at 700 yards, but I have not shot it enough to know if it can compete with the 109 Bergers in a more thorough comparison. I've got a large stock of the Bergers and they cost way less than the ATips, so I think I'll stick with them for now.

For powder, my results agree with the advice you received above: Varget, CFE 223, Lever all have worked well for me. I have separate loads optimized for cold and warm weather and have seen Varget to be a little less temperature sensitive. I picked up a few pounds of Accurate 2520, which some report as excellent for 6 ARC but have not tried it yet. I've got plenty of Varget and CFE 223 so I'm not in a rush to work up a 2520 load. Cross your fingers that Lapua will get off their ass and make 6 ARC brass sooner rather than later.

 

[supercorndogs]

Varget works well. Lever and cfe 223 are too temp sensitive, no brass as of yet. I have tried to form brass from 6.5 and it seems it loves to develop a belt. Hopefully someone will make better brass.

The belt is more likely going to be too deep of chamfer on the chamber or something like that. This sounds like the same problem people have had with Lapau Grendel brass, with the web not being thick enough and the unsupported part of the brass starting to budge. What kind of brass are you forming? What kind of barrel?

I had an RCBS small base 264LBC die that would put belts on cases.

 

[morning would]

I shoot 6 ARC in both semi auto and bolt guns. But, having just built a dasher, the bolt gun will probably go bye bye. So I started messing around with my AR in 6 ARC again recently. While it shoots 107 smk’s and 105rdf’s good, my particular rifle likes 95 VLD’s probably the best. It shoots a 28gr load of cfe223 into anywhere from .4 to about .65 depending on the day. The problem is, 28gr of CFE is on the slower end at about 2475fps. So I set out to hopefully find a bit more speed and maybe a bit more consistency. Rifle is made by APF and they use an 18” proof Carbon Fiber barrel. I know that CFE and Lever suck for their temp sensitivity, but they really seem to shine in both the 6 Arc and 6.5 Grendel. It was mid 90’s at the range today and I saw no pressure signs on any load other than the very top end of the CFE range and that was only a small ejector swipe. Today I focused on the upper end of charge ranges for an AR in all powders I tried. so I was pretty happy to not see issues. I will be stoked to get some of that new starline brass for the arc as all of mine is Hornady with 5-6 firings. Primer pockets are really starting to get loose. Anyways, everything you see is with a 450 primer and a 95 Berger VLD Target that fits in a mag and is at 1.671” BTO. Charge weights and 3 round group sizes are shown. I will chase some of these further with both velocity readings and seating depth testing to see what shakes out. The goal is a load that shoots consistent .5’s at 2600 or so. Ask questions if you have any. I have shot quite a bit of 6 ARC. Next outing will be 8208 XBR, Winchester 748, Varget and Shooters World Precision. Ignore the 2 groups of 308 at the bottom of the second sheet. I was trying to see the difference between a 210 and 215M large rifle primer. I was also fire forming new Lapua brass at the same time.

 

[db2000]

I shoot 6 ARC in both semi auto and bolt guns. But, having just built a dasher, the bolt gun will probably go bye bye. So I started messing around with my AR in 6 ARC again recently. While it shoots 107 smk’s and 105rdf’s good, my particular rifle likes 95 VLD’s probably the best. It shoots a 28gr load of cfe223 into anywhere from .4 to about .65 depending on the day. The problem is, 28gr of CFE is on the slower end at about 2475fps. So I set out to hopefully find a bit more speed and maybe a bit more consistency. Rifle is made by APF and they use an 18” proof Carbon Fiber barrel. I know that CFE and Lever suck for their temp sensitivity, but they really seem to shine in both the 6 Arc and 6.5 Grendel. It was mid 90’s at the range today and I saw no pressure signs on any load other than the very top end of the CFE range and that was only a small ejector swipe. Today I focused on the upper end of charge ranges for an AR in all powders I tried. so I was pretty happy to not see issues. I will be stoked to get some of that new starline brass for the arc as all of mine is Hornady with 5-6 firings. Primer pockets are really starting to get loose. Anyways, everything you see is with a 450 primer and a 95 Berger VLD Target that fits in a mag and is at 1.671” BTO. Charge weights and 3 round group sizes are shown. I will chase some of these further with both velocity readings and seating depth testing to see what shakes out. The goal is a load that shoots consistent .5’s at 2600 or so. Ask questions if you have any. I have shot quite a bit of 6 ARC. Next outing will be 8208 XBR, Winchester 748, Varget and Shooters World Precision. Ignore the 2 groups of 308 at the bottom of the second sheet. I was trying to see the difference between a 210 and 215M large rifle primer. I was also fire forming new Lapua brass at the same time.

View attachment 8179594View attachment 8179595

I’d strive for 5 shot minimum and probably 10 shot groups to really give you an idea of the load and your ability.

 

[morning would]

I’d strive for 5 shot minimum and probably 10 shot groups to really give you an idea of the load and your ability.

That’s typically what I do. But this is simply testing to see if something jumps out at me before I chase it down the rabbit hole. Kinda like the 308 that is at the bottom of the second pic is 5 shots each so I can simply look at the difference between a regular and a standard large rifle primer at a known good load for my rifle. But I am not going to shoot up an extra 2-7 Bergers on something that won’t hold together at even 3 shots. That makes no sense to me, but you do you. Was simply answering the call of the title of the thread about 18” 6 ARC AR loads, though not specifically with 105 or 108 load since the OP said they could find very little data, here are some powders not always listed for 6 ARC like N140 or AR Comp. I figured sharing any info on a cartridge where not much exists may help someone. Kinda like if I had a load that works with 58gr v max’s, I might have shared that as well.

 

[db2000]

Just saying for example, 2-7 more shots on these two loads may have produced an incredible pattern. You can’t know because you didn’t take them. You can’t say these weren’t panning out with any confidence. I get it if they’re already 1 MOA but you could be missing out. I’m not criticizing you, just putting it out there.

 

[morning would]

Completely understand. I just happen to do it maybe a little different. I shoot 3’s, then I shoot 5’s with stuff I liked and then I shoot with the magneto speed attached if those pan out so I can make sure I like the velocity I’m at. Then it’s fine tuning with seating depths or primers, etc. I guess it’s because I love the puzzle solving aspect of reloading, so I just have a particular method I have been constantly refining. Plus, I have received a lot of help over the years from many different forums. I just like to try and help if I can, even if it’s just in a small way. I appreciate the further explanation though as I may have taken it differently than you intended due to the fact that our written word usually leaves a lot to be desired when it comes to deducing actual intent.

BTW, I know you asked about 58gr v max’s earlier. If you need results from the 75’s or 87’s let me know. I have pretty good loads for both from my particular rifle.

 

[FuhQ]

The belt is more likely going to be too deep of chamfer on the chamber or something like that. This sounds like the same problem people have had with Lapau Grendel brass, with the web not being thick enough and the unsupported part of the brass starting to budge. What kind of brass are you forming? What kind of barrel?

I had an RCBS small base 264LBC die that would put belts on cases.

Same here with my early set of RCBS .264 LBC dies for my 6.5 Grendel. Pretty sure it was cut WAY too tight with an improperly spec’d reamer. I ended up just buying a new set of actual RCBS 6.5 Grendel dies when they became available…Problem solved.

 

[supercorndogs]

Same here with my early set of RCBS .264 LBC dies for my 6.5 Grendel. Pretty sure it was cut WAY too tight with an improperly spec’d reamer. I ended up just buying a new set of actual RCBS 6.5 Grendel dies when they became available…Problem solved.

I polished the die with some 600 grit until it stopped doing it. Then bought some new dies when they came available. All I ever did with the 264 LBC dies was size some 7.62x39 brass to fire form.

 

[db2000]

Completely understand. I just happen to do it maybe a little different. I shoot 3’s, then I shoot 5’s with stuff I liked and then I shoot with the magneto speed attached if those pan out so I can make sure I like the velocity I’m at. Then it’s fine tuning with seating depths or primers, etc. I guess it’s because I love the puzzle solving aspect of reloading, so I just have a particular method I have been constantly refining. Plus, I have received a lot of help over the years from many different forums. I just like to try and help if I can, even if it’s just in a small way. I appreciate the further explanation though as I may have taken it differently than you intended due to the fact that our written word usually leaves a lot to be desired when it comes to deducing actual intent.

BTW, I know you asked about 58gr v max’s earlier. If you need results from the 75’s or 87’s let me know. I have pretty good loads for both from my particular rifle.

I took out the 58s and left the damn chrono at home
Went ahead and broke in my 25CM barrel but freaking amateur hour. Guess I’ll find out next time. Gonna start at 31.0 A2230 and move up hopefully.

 

[troupe]

Just a heads up on Brass. Creedmoor Sports has Starline 6mm ARC brass in stock. I just purchased 200 pieces. Hope that helps anyone looking.

 

[db2000]

84F 56% 29.88 in

Seekins 6 ARC Shaw 18” SS 1:7.5
Magnetospeed V3

Hornady 58 gr VMAX
A2230
Hornady brass x 5 (several primers fell out prior to shooting due to loose pockets)
205M
BTO 1.6650
COL 1.4900
31.0 3335, 3339, 3332, 3317 SD 9.6 1” no pressure

31.3 3393, 3377, 3413, 3389, 3408 SD 14.5 0.8” (4 0.5”) no pressure

31.6 3416, 3431, 3416 SD 8.6 0.8” no pressure

31.9 3444, 3426, 3412 SD 16.0 1.25” no pressure

32.2 3468, 3466, 3474, 3476 SD 4.6 0.5” x 3 no pressure


32.5 3507, 3506, 3497, 3506 SD 4.6 1” mild pressure ring from extractor

 

[Gtscotty]

I've had good luck with the 29.1gr - 29.3gr range of LVR under 100gr TGK, 105gr MB, and 108gr ELDs in my 18" and 21". Seems to be kind of a sweet spot.