6mm ARC Brass Forming

[Helidriver]

Is it possible to take a 6.5 Grendel case and neck it down to 6mm ARC? As far as I can tell the parent case is the same as the Grendel and the shoulder is only set back on the ARC .030" from the Grendel. If it is possible, is it simply done by running a Grendel case into an ARC FL die? I've got a bunch of unfired Lapua Grendel brass and it sure would be a cheap solution. I just bought a Uintah Precision upper in 6 ARC to try something new.

In all my years of reloading I've never taken brass from one caliber to another so this is completely new to me.

 

[Pvt.Donut]

You could, you'll probably have to do it in 2 steps. Take the neck down to 25 Cal, then down to 6mm. It would be easier to fireform 6mm PPC brass.

 

[James40004]

One step, made 6ppc from 6.5 Grendel for cheap cases

 

[Helidriver]

Well you guys were right. It was pretty straight forward. I took 25 Lapua Grendel cases (4x fired) and sized them for 6 ARC. After sizing I had to trim them quite a bit and I noticed some neck wall variations so I turned them, annealed, then steel pin tumbled. I’m going to cut open two of them just to be sure nothing unexpected has happened during the processing. Below is the result. I must say I’m pretty happy with them.

 

[James40004]

Before you load them try an empty case to make sure it will. chamber in your rifle. Had my ppc dies to bump shoulder .002 from fired case, when I made the brass from 6.5 the base and body was too large to chamber and had to reset dies a little tighter. Ymmv

James

 

[Helidriver]

Good point. I will do that. The sectioned cases look good. No thinning to distortions that I can see.

 

[Helidriver]

I finally made it to the range with my 6.5 Grendel to 6 ARC hand loads. They shot great! Starting load was averaging 2609 FPS, single digit SDs. Best group was .52 with average right at .75. My AR marksmanship needs some serious work and I know the gun would have done better if I was better tuned however it certainly exceeded my expectations.

Now I need to work up the load and get a little more speed, 2750 is my goal.

 

[FCS]

How long is barrel?
What bullet are you using?

 

[Helidriver]

How long is barrel?
What bullet are you using?

22”, 108 ELD-M, 29gr Power Pro 2000-MR, COAL 2.245” (I have no idea how much jump that is, I haven’t measured it yet but that’s max with the Amend2 mags).

 

[FCS]

I don't have a 6 ARC running yet but do have a 6mmAR. Bartlien barrel, +2 gas, 22" long and with Berger 108 MBTs in virgin Lapua brass it shoots best at 2660-2675 fps.

I suspect you'll get best accuracy and brass life with the 6 ARC at similar velocities.

 

[sprad05]

I'm running a cartidge very similar 6mm Chyeeta, and it basically uses grendel necked down to fireform, then just bumping the shoulder 3 thou after fireforming

 

[Dolomite_Supafly]

Anyone know a source of brass for the ARC or Grendel. Looking like I am about to buy them for $1 each.

 

[FCS]

Anyone know a source of brass for the ARC or Grendel. Looking like I am about to buy them for $1 each.

Preference on brand of 6.5 Grendel brass?

 

[Dolomite_Supafly]

Preference on brand of 6.5 Grendel brass?

No preference at all. Beggars can't be choosers.

 

[jeffreybehr]

StarLine makes and sells them, but they're out of stock.. Only 48cents each in 500s.

6.5 Grendel Brass - Small Rifle - Brass Cases

 

[Dschapp44]

Welcome to ON THE MARK - Everything for the Marksman!

Just got brass from these guys but just going 6mm AR for simplicity’s sake

 

[betolatinlu]

Well you guys were right. It was pretty straight forward. I took 25 Lapua Grendel cases (4x fired) and sized them for 6 ARC. After sizing I had to trim them quite a bit and I noticed some neck wall variations so I turned them, annealed, then steel pin tumbled. I’m going to cut open two of them just to be sure nothing unexpected has happened during the processing. Below is the result. I must say I’m pretty happy with them.

View attachment 7414302View attachment 7414303

I tried what you described and no way in hell will that work for me. I have Hornady Custom dies and it just won't work. I've made three wildcats where I had to come uv jv,

One step, made 6ppc from 6.5 Grendel for cheap cases

I tried that today and trust me, for me it doesn't work. I've been reloading since 1971 and I've made 3 wildcats in that time. I spent an trying to go from 6.5 Grendel to 6mm arc It's not happening. I've gone from 6mm to. 22 no problem. I've gone from. 308 Norma mag. to. 25 caliber. But this one beat me. I've met my match. I guess that for now I'm not gonna shoot my new 6mm arc rifle.

 

[Baldy52]

I just tried 6.5 Grendel Norma brass conversion in RCBS AR small base dies.
I can’t get them to chamber unless slam the BCG a few times.. dummy round with no primer. I have the die set as low as possible.
is this a shoulder bump problem?
woukd a 6 ppc full size die help at all? If so would one fire form the brass after going through the 6Ppc
Thanks really want to shoot my new build!

 

[Baldy52]

I am going to try to use the Redding 6 PPC body die on the cases and see if this resolves my issues of chambering the Converted grendel cases

 

[Baldy52]

I tried what you described and no way in hell will that work for me. I have Hornady Custom dies and it just won't work. I've made three wildcats where I had to come uv jv,

I tried that today and trust me, for me it doesn't work. I've been reloading since 1971 and I've made 3 wildcats in that time. I spent an trying to go from 6.5 Grendel to 6mm arc It's not happening. I've gone from 6mm to. 22 no problem. I've gone from. 308 Norma mag. to. 25 caliber. But this one beat me. I've met my match. I guess that for now I'm not gonna shoot my new 6mm arc rifle.

I have same issues. Will let you know if the PPC body dies works

 

[jeffreybehr]

Here...

Lapua Brass 220 Russian Box of 100

Lapua World-class brass begins with high-quality raw materials and superior smelting and metallurgical competence. Throughout the production process,...

www.midwayusa.com

...is another alternative for 6ARC brass, the Lapua 220 Russian.. It's expensive at a buck-and-a-half each, but it is super-hi-quality Lapua brand.. I have almost 200 of these coming that have been fireformed into 6PPC and neck-turned.. What I don't have is a chamber to check them in; my Uintah SP-15 is apparently still a few weeks away.

 

[Baldy52]

Here...

Lapua Brass 220 Russian Box of 100

Lapua World-class brass begins with high-quality raw materials and superior smelting and metallurgical competence. Throughout the production process,...

www.midwayusa.com

...is another alternative for 6ARC brass, the Lapua 220 Russian.. It's expensive at a buck-and-a-half each, but it is super-hi-quality Lapua brand.. I have almost 200 of these coming that have been fireformed into 6PPC and neck-turned.. What I don't have is a chamber to check them in; my Uintah SP-15 is apparently still a few weeks away.

Thanks for suggestion !

 

[alamo5000]

I just tried 6.5 Grendel Norma brass conversion in RCBS AR small base dies.
I can’t get them to chamber unless slam the BCG a few times.. dummy round with no primer. I have the die set as low as possible.
is this a shoulder bump problem?
woukd a 6 ppc full size die help at all? If so would one fire form the brass after going through the 6Ppc
Thanks really want to shoot my new build!

Take one of those cases and make a seated dummy round (no live primer/no powder) and paint it with a sharpie marker. Use the color of your choice. Red has a nice contrast on the brass. Then chamber the dummy round by dropping it in the barrel and closing the bolt on it. Eject it very slowly and you can see most of the time where contact is being made.

I helped my dad solve a problem using this method. He wanted to shoot his new Christmas present but some of his rounds wouldn't chamber at all. Turns out he had his die set up incorrectly in the press. It could be something as simple as that but it could also reveal something else. Who knows.

 

[IowaGeologist]

How much success are people having turning 7.62x39 into 6 ARC? Any need to turn necks if doing it? Don't even have an ARC yet, but think it might be something fun to try.

 

[bodhisafa]

^this I am wondering myself.
Can the 220 Russian be turned into the 6 arc?

 

[skyrep]

i've been reloading the 6mm ARC for awhile now. i'm using a wilson bushing die to convert 6.5 Grendel Brass to 6mm ARC. I'm on my 3rd reloads on the Hornady Brass, 2 on Starline Brass. And just converted the Grendel Lapua Brass. Have not had any issues. Both for Bolt Action and Gas Gun.

 

[Dolomite_Supafly]

Can anyone send me a couple of pieces of fired 6ARC brass? I don't care if they are junk as I am needing a piece of fired brass to set the head space. I have a reamer but cannot find a head space gauge in stock anywhere.

I will gladly pay any out of pocket expenses to put it in my hand.

 

[Baldy52]

Short action customs has head space Guage’s.
they have multiple 6mm and looks like you get the 30 degree one for 6 ARC

 

[spife7980]

Short action customs has head space Guage’s.
they have multiple 6mm and looks like you get the 30 degree one for 6 ARC

Gauge. Not comparator.

 

[James40004]

The neck turned 220 russian into 6ppc is probably very thin. Most common is .262 neck.

7.62x39 into ppc makes a really thick neck that has to be turned. Sure it will for 6 arc too. Bright side is the 39 lapua brass is large rifle size and those primers seem to be easier find right now.

Norma makes a 6ppc usa brass it has a 270-272 neck when loaded. Should be correct neck for arc. Load the bullet long into the lands and fire form

James

 

[bodhisafa]

what about neck down 220 Russian to 20 cal and fireforming to the ARC body dimension?

 

[usbp379]

The nice folks at Hornady say they are running 6 ARC ammo next month. The oldest backorders at places like Midway will be getting filled first.

In the meantime, I have sized 6 ARC from 6.5 Grendel. It goes easily appears to be drama-free other than needing a fairly decent trim. Resized cases seem to run about 1.52" +/- after necking down.

Regarding 220 Russian; from case dimensions it looks like the 220/243 cases might not headspace by merely necking up. It might be necessary to try to size to 6.5 and then create a false shoulder with a 6mm die. Anyone messed with this yet?

Plan B might be to have Whidden or Hornady make a hydraulic die for 220 Russian to 6 ARC. A pricey option and probably not worth it unless you want to do it for the fun or have a couple pieces of Russian brass lying around.

 

[newageroman]

I've been converting Starline Grendle to ARC with great results. they no longer have grendle brass but they do have grendle basic brass. I have access to an AMP annealer, so I'm wondering how bad it would be to form from the basic brass.

found this:

You are being redirected...

That is good news about Hornady getting brass.

 

[supercorndogs]

How much success are people having turning 7.62x39 into 6 ARC? Any need to turn necks if doing it? Don't even have an ARC yet, but think it might be something fun to try.

I just tried to make some 6.5 Grendel with some 7.62x39 brass, and it needs neck turned.

This post was incorrect. I had some bad pressure signs on my fire forming loads. I tried to push a bullet into the neck and it did not go. I just figured out this was due to a flat spot on the neck from extraction. Not due to the neck being so thick it could not expand enough to release the bullet.

 

[supercorndogs]

Edit to correct my post.

 

[Dschapp44]

Any updated on success or tips sizing 6.5 grendal lapua down to 6 arc? Will I need to clean up the necks?

 

[newageroman]

you may want to check the other thread for lapua conversion info. I believe I saw some details about the lapua cases being thinner around the base leading to a Grendel Ring.

As far as cleaning up the necks, not sure for Lapua, but Starline conv is GTG IMO.

 

[mason.ostrom]

I just fireformed a couple of 220 Russian cases to 6MM grendel and it worked well. I did neck up to 6.5 then down to 6MM to create a false shoulder to headspace off of. Used bullseye and cream of wheat. The only issue I had is that the case necks turned out thinner than my other brass, but seems to be very close to the few pieces of 6ARC Hornady brass I have found and measured. Necks were 0.0142 ish. Als the final case was a bit short for 6mm grendel at 1.485 vs 1.515 when necking down 6.5 grendel. This should not be an issue with 6ARC. Long story short, i think 220 Russian should work great to form 6ARC with.

 

[fifdynutz]

I found some new starline grendel brass, simply lubed it, ran it into my hornady 6arc die a couple times, trimmed it, and it worked great. chamber perfect in my faxon barrels, and match up with my new hornady 6arc brass for headspace perfectly. every now and then i had to tap the expander tip on the trimmer into the neck a bit to spin freely but no big deal. Going to load 5 test rounds tonight and fire them to verify.

 

[GONE BAD]

Okay, so I had (1) 6.5 grendel piece of brass that I had picked up somewhere.
I lubed it and ran it through the 6arc die and the neck pushed down into the shoulder. It was destroyed!

Question is; should I have trimmed the neck down before I tried to resize the case?
Is there a certain sequence to resizing 6.5 grendel to 6arc?
Thanks

 

[newageroman]

Oh no! That is weird. I've destroyed some by having them a little off center so the edged of the neck catches on the bottom of the die, but that's like 1/100 or so.
What type of brass is it? some may be thinner.

Mine converted with moderate effort. I was surprised how easy it was really.

 

[fifdynutz]

^^ same...i found it to be surprisingly easy

 

[GONE BAD]

Okay,
I was just wondering. Thanks
It was for future reference.

 

[r.tenorio671]

....just finished converting 200 virgin new Starline 6.5 Grendel brass to 6ARC using Hornady dies, encountered no issues or collapsed walls. After getting the sizing die set up for proper shoulder bump, zipped thru the 200 cases with no problems. I did a sample test of 10 un-annealed cases and 10 pre-annealed cases and found that the pre-annealed cases had more consistent shoulder bump (1.188") than the un-annealed cases and required less force during the sizing. After sizing, trimmed to 1.488", which is 0.002" below SAAMI max spec of 1.490" (Hornady recommends trim length of 1.475", Hodgdon recommends 1.480"). Cases chamber with no issues in my BA barrel. Due to the limited component availability, my first test loads will be Nosler 70gn Varmageddon FB over 8208XBR and some Nosler 105 RDF's over W748. If I can get some 85-95 grain projectiles I plan to test AR-Comp with them.

 

[newageroman]

Excellent work! Good test for annealing before forming. I've formed about 1200 cases so far minimal issues. I'm about to try neck turning some for ultra match rounds.

I also found that my chamber has a very long neck and I can trim to 1.195" and sell chamber sized case and lock the bolt with ejector and extractor removed so that is my trim len.

I also found after mandrel sizing fire formed cases and shoulder bumping 4 thou that only 15 cases out of 300 needed to be trimmed! That was a great day!

Hope you get some more components and good luck!

 

[r.tenorio671]

Excellent work! Good test for annealing before forming. I've formed about 1200 cases so far minimal issues. I'm about to try neck turning some for ultra match rounds.

I also found that my chamber has a very long neck and I can trim to 1.195" and sell chamber sized case and lock the bolt with ejector and extractor removed so that is my trim len.

I also found after mandrel sizing fire formed cases and shoulder bumping 4 thou that only 15 cases out of 300 needed to be trimmed! That was a great day!

Hope you get some more components and good luck!

...I did measure neck OD and ID after resizing and all was within SAAMI spec so I don't feel neck turning will be required. After my first firing I'll re-measure to note if any significant change occurs. During my seating tests neither the Vgdon or RDF's could be pushed in nor did they change when testing the feeding from mags (Duramag & Elander) when hand cycling or dropping bolt via bolt release. I did have to pull a bunch of the RDF's due my scales battery dying out and concerns over overcharging and using a kinetic puller just wasn't cutting it :-( ended up using my Hornady bullet puller but had to "adapt" using a 22 cal insert. Yep, it marked up the bullets but no worries, these 1st loads are for pressure testing only. During the pull, they were in there pretty good so I know neck tension is GTG and not a worry. Reseating them in the same cases didn't feel any different and they still won't move when pressing them against the bench

 

[newageroman]

Looks good. I had a kinetic puller pop a primer off on a loaded 30-06 garand round a decade ago. I still remember the primer flying through the air in my old place. I wrapped that kinetic puller in my dirty shorts threw it in the trash and never looked back. I have Grip n pulls now and they are spensive but are super easy/quick and awesome.

 

[Adam B]

has anyone successfully turned Lapua 220 Russian into 6 arc? I have 200 that I want to do but am curious what their process was.

 

[newageroman]

AMP annealer sitting in the garage. havent been able to plug it in yet, but tomorrow should be fun. I've got hundreds of cases ready to anneal then neck turn. Found primers today (limit 400), and got some LeverEvolution and some bullets and powder for 300PRC too. great day next week should be fun. My ELR mentor just ran poke the Bear in Va, so gonna bend his ear on how the match went.

 

[Adam B]

has anyone successfully turned Lapua 220 Russian into 6 arc? I have 200 that I want to do but am curious what their process was.

Many thanks to

James40004​

it was super easy to do in my bolt gun. 90% max charge and jam the bullet. The cases came out perfectly!