Forming 6mm ARC brass from something else?

[chinewalk]

I need 6mm Arc brass and have a couple hundred dollars of it backordered from December with no hope in sight. Something has to give.

I have a WTB in swapping and selling concerning 6mm ARC brass and a couple of kind folks mentioned forming it from something else over there. Rather than get spanked for asking these question in the WTB, I thought it best to start one here.

I do have some 7.62x39 brass, but probably not much else to start a forming process. In addition, I really wasn't wanting to form brass, but times are tough. I really don't have the experience (nor tools in some cases) to do a rather complex conversion and was hoping for a simple one. I did find articles on forming 6.5 Grendel which appears to be quick and simple, unfortunately it seems to be as scarce as 6mm ARC brass.

I figure I am going to learn a lot from this exercise (including history). As one member pm'ed me "Well, the 7.62x39 begat the 220 Russian, the 220 Russian begat the 6.5 Grendel, which begat the 6mm ARC" (thanks Corey!). He also pointed me to a site that has 220 Russian brass.

So, before I take off unprepared for the quest, if anyone has some ideas on the best (or available) approach to take to make 6mm Arc brass, it would be much appreciated!

Thanks,

Ed

[jakharath]

Howdy! You may be able to form it from 220 Russian or 6.5 Grendel.

[Mk42gunner]

I've not kept up on all the new cartridges and their dimensions, but what about the 6mm PPC as a donor? IIRC it was based on the .220 Russian, so maybe...

Unless you want to invest in forming dies, I would suggest starting with a small quantity of brass to test your conversion process. Also be prepared for a lot of failures and ruined cases in the learning process.

Robert

[chinewalk]

I was afraid this might go further that I wanted to go.

I did read up on several internet articles since posting this and I really don't want to be buying forming dies or start annealing cases, blowing out shoulders and several other unpleasant things that I saw reported. I had rather be setting the new rifle up for long range shooting, but back to the no brass issue. I might just pick up my .338 Lapua again and continue with it for a while longer to scratch the itch (I still have components for it). Maybe the brass will finally be available by then.

Thanks!

Ed

[chinewalk]

I've not kept up on all the new cartridges and their dimensions, but what about the 6mm PPC as a donor? IIRC it was based on the .220 Russian, so maybe...

Unless you want to invest in forming dies, I would suggest starting with a small quantity of brass to test your conversion process. Also be prepared for a lot of failures and ruined cases in the learning process.

Robert

Thanks for this input sir! I'm still peeling this onion to see how painful this might be!

Ed

[tdoor4570]

From what I just read on the 6mm arc it is a step backward from the 243 win. I would just load and use the 243 with the same bullet that is in the 6mm arc. also the 243 will work in the AR style of rifles if that is what you want.

[chinewalk]

Definitely a good suggestion my friend! But, l already have the Arc in a AR-15, just no brass. I bought it before I realized brass was going to be a problem or I might have done something else for sure.

I did look at the .243 which goes into a AR-10 as we know, but wanted something in the smaller package. I probably would have went with the 6.5 Creedmoor if I had went with the AR-10 though. Then while considering that, I would have probably oscillated and bought a bolt action instead of an AR-10 to run the Creedmoor out of. Ha! And before long, I would have had something almost as expensive to own, shoot and carry as the .338 Lapua I have. This stuff is fun ... as long as we can get components and have that second job to feed it.

I appreciate the input!

Ed

[chinewalk]

I'm in contact with SOFMatchstaff (he makes 6PPC form dies) and with his suggestions (and possible forming dies) entertaining a 7.62x39 to 6PPC to 6mm ARC forming project.

It does appear that some Hornady factory ammo is now becoming available and I ordered a box of Arc this morning to get my long range setup project started. However, 7.62x39 brass is cheap and plentiful ... 6mm Arc is neither, so if I can build my own without a stupid amount of money and effort, I'm going to check it out.

I'll probably bow out now, but if I do take on the forming project and make a product that is as accurate as the factory cases, I'll probably update this one or open another thread to let you folks know the outcome (and my opinion if I would ever do it again! Ha!).

I really do appreciate everyone's input and you folks take care out there.

Ed

[SOFMatchstaff]

A little up-date/ correction, I Do Not make any forming dies( I wish I was that skilled) but I do have the 7.62x39 to 6mmPPC form die set and it does easily make a suitable case ready to finish size to either PPC or the 6mmARC. I set the form dies up in the RL450 and ran off some dummy cases out of Berdan junk and when properly set for sizing depth it made a primary case every time the handle was pulled. No annealing, just clean and lubed, three operations at once. It took about 30 min to set it up and tune the die limits and run off 2 dozen cases. I would think it wise to anneal before fire forming, or maybe before the first trip into the PPC or ARC size die, but as I dont have either die set(or gun) I cant say what the result would be at the shoulder set back. I'm sending the dummy samples to ED and He can do the fine tune for the fire form phase. The AR chamber might not like the fire forming stage, not like a bolt gun anyway. Have to wait and see what the final size results look like.

[chinewalk]

Whoops! My bad. I thought you actually make the dies. Never the less, I bet you are a lot more skilled than I am. Ha! This probably will be interesting.

I appreciate the help!

Ed

[barkerwc4362]

I form my 6mm ARC from Lapua 6.5 Grendel. I trim them first, run through a 6mm ARC sizing die (without the de-capping stem), then run them through a 6mm ARC sizing die with the de-capping pin installed. I final trim and de-burr before I tumble. Using this system I don't need to neck turn for my McGowen 22" AR-15 barrel.

Bill

[dougader]

I heard the same from a guy yesterday. He just runs his 6.5 Grendel into a 6mm ARC size die, trims, deburrs, loads and shoots.

[chinewalk]

I heard the same from a guy yesterday. He just runs his 6.5 Grendel into a 6mm ARC size die, trims, deburrs, loads and shoots.

Thanks! Sounds like the easiest way to go if I can find Grendel brass. It appears to be stored in the same boxes with the 6mm Arc right now though. The nowhere to be found box. Maybe Starline will put it back on the backorder status soon.

Appreciate it! Options are good!

Ed

[SOFMatchstaff]

chinewalk, a care package is on the way, use the Berdans to experiment with and the Federals to try some fireforming once the dies are adjusted using the Berdans. enjoy.

[chinewalk]

Thanks again! I do appreciate all of your effort!

Ed

[usbp379]

@chinewalk
@SOFMatchstaff

Any updates on forming 7.62x39 to 6mm ARC? Thank you!

[downzero]

From what I just read on the 6mm arc it is a step backward from the 243 win. I would just load and use the 243 with the same bullet that is in the 6mm arc. also the 243 will work in the AR style of rifles if that is what you want.

243 Winchester will not fit in an AR; it's way too long.

I had a 6mm Fat Rat and I regularly made the brass from 6.5 Grendel, so that certainly can happen. People talk about making it from 7.62x39 or 220 Russian or similar, but those are a greater difference.

[chinewalk]

@chinewalk
@SOFMatchstaff

Any updates on forming 7.62x39 to 6mm ARC? Thank you!

Not really. I don't really want to add another step in here just to get something that will fit into my 6MM ARC but has all kinds of consistency differences that will shoot like crap at long ranges. I haven't had much luck in getting 7.62x39 sized into 6MM ARC consistently enough that even makes me feel comfortable with spending the time, powder, bullets and those accursed high dollar primers to try reformed brass over 100 yards. If I was just trying to get something formed for 50 yard blammer loads, I might look at it closer, but I usually don't do blammer type shooting. At this point, I'm losing hope and spending more time with my .338 Lapua as I have cases, bullets, primers and powder for it.

Note, that I don't normally get into reforming brass so I am not a master at it and others might have a lot better experience and advice. But again, with the stupidity of primer and powder prices at the moment, I'm really not wanting to experiment.

I must say that I am disappointed in the availability of 6MM ARC brass from at least Hornady as they built this round and hyped it. Mine is a AR-15 .75 MOA shooter with LeverEvolution and Berger 105 target bullets. But, I'm considering dumping it because as of today, to get brass I have to buy high dollar Hornady factory loads that so far have not really shot well in it or as this thread has demonstrated, form your own which what little I have tried also does not shoot well after all the effort.

As a side note, I have a 6MM ARC Hornady brass order that has been on backorder for over one year and five months so far and Hornady says they have no clue when it will ever become available.

The future does not seem to look too bright.

Take care out there.

Ed

[rockrat]

See if you can get a cheap set of Lee dies for the 6.5 grendel. Form the x39 brass to 6.5 grendel and then run that case thru the ARC die. I go this way to make 6 grendel (243 lbc) and use 6mm ppc dies to load the 6mm grendel. I did find some 6.5 grendel brass a few weeks ago, but it was $1 each. I have plenty of x39 so I go that route.

[chinewalk]

See if you can get a cheap set of Lee dies for the 6.5 grendel. Form the x39 brass to 6.5 grendel and then run that case thru the ARC die. I go this way to make 6 grendel (243 lbc) and use 6mm ppc dies to load the 6mm grendel. I did find some 6.5 grendel brass a few weeks ago, but it was $1 each. I have plenty of x39 so I go that route.

Yeah, Grendel brass is as hard to find as ARC. I might try this as I am setting up a buddy's Grendel and have his RCBS dies. He wound up having to buy Lapua brass for his Grendel ... but it was there.

I appreciate the advice.

Thanks!

Ed

[usbp379]

6.5 Grendel is about as straightforward as case conversation gets. Full-length size to bump the shoulder then trim. Trim quite a bit, actually. Without some kind of motorized trimmer it would be nigh on impossible.

Regarding conversion of 7.62x39 into 6 or 6.5; what are ya'll doing about the drastic AK case taper? About the only way to get rid of the taper is to load and shoot. Or hydro-form. Whidden and Hornady make water forming dies. I assume a few other companies do as well.

Sent from my SM-G970U using Tapatalk

[chinewalk]

See if you can get a cheap set of Lee dies for the 6.5 grendel. Form the x39 brass to 6.5 grendel and then run that case thru the ARC die. I go this way to make 6 grendel (243 lbc) and use 6mm ppc dies to load the 6mm grendel. I did find some 6.5 grendel brass a few weeks ago, but it was $1 each. I have plenty of x39 so I go that route.

Well, I'm in Oklahoma a week before Memorial weekend and the weather is doing what it normally does here this time of year ... rain and storm.

So, I grabbed up some 7.62x39 cases, 6.5 Grendel sizing die and 6MM ARC sizing die to attempt to cure the boredom and gave it a whirl. Going from 7.62x39 to 6.5 Grendel was easy. Getting the neck and shoulder formed thru the ARC sizer obviously took more time. I would put a case in the shell holder, raise case as far as it would go, screw the ARC sizer until it touched the case, size, turn die about 1/4 turn down and repeat until I had enough neck to stick out of my Wilson trimmer case holder then I would trim back to 1.475. After that continue on with slowly size/turn die until the sizer touched the press. I managed to get two usable cases out of ten with shoulders that weren't pushed back, so apparently I am still doing something wrong.

And it is still storming.

[Finster101]

I would think working the brass that much annealing might be a good place to start.

[usbp379]

I would trim back to 1.475.

Just a suggestion but I wouldn't trim that short. 1.490" will probably work better. You're going to lose a few thousandths upon firing when the taper is formed out of the case.

Sent from my SM-G970U using Tapatalk

[chinewalk]

6.5 Grendel is about as straightforward as case conversation gets. Full-length size to bump the shoulder then trim. Trim quite a bit, actually. Without some kind of motorized trimmer it would be nigh on impossible.

Regarding conversion of 7.62x39 into 6 or 6.5; what are ya'll doing about the drastic AK case taper? About the only way to get rid of the taper is to load and shoot. Or hydro-form. Whidden and Hornady make water forming dies. I assume a few other companies do as well.

Sent from my SM-G970U using Tapatalk

Load and shoot is the only way I know of. Burn more powder, primers and bullets which is why I haven't done much of this. But...I can't get ARC brass.

[chinewalk]

I would think working the brass that much annealing might be a good place to start.

Probably so. That might keep the shoulders from bulging.

[usbp379]

Look at item 933790347 on gunbroker.

Sent from my SM-G970U using Tapatalk

[chinewalk]

Just a suggestion but I wouldn't trim that short. 1.490" will probably work better. You're going to lose a few thousandths upon firing when the taper is formed out of the case.

Sent from my SM-G970U using Tapatalk

I will certainly take that into consideration if I can keep the shoulders from collapsing/bulging. I just grabbed the minimum trim length for the 6mm ARC to try to get around the bulging, but you are right ... they probably would be too short once fired and 1.490 is the max trim length.

Thanks,

Ed

[chinewalk]

Look at item 933790347 on gunbroker.

Sent from my SM-G970U using Tapatalk

Interesting! Thanks!

Ed

[Rapier]

I make 6.5 G out of 7.62x39 Win brass, only. The other brass is too soft or too thick. If you had a G chamber it would help, full length size, one pass, to fit the G chamber, trim and chamfer in and out. If you try to use military 7.62 brass chances are the neck will be too thick.
If you FL size to G then outside turn the neck, leaving a hair line not turned, lube in and out before you size to 6mm ARC you may have better results.
You will be fire forming the 6mm in any case, so you can headspace using the shoulder or set a bullet out to engage the lands to fire the cartridge. Fire the set out bullet with a starting load and lube the case before firing, so it can not stretch the web.
Normally, you might toss them, but today is not normal when it comes to brass avability.

[rockrat]

Hmmm. I go straight from 6.5G to 6G in one pass, but I don't push shoulders back. Annealing the neck of a few cases and try it again.
Usually this time of year its 100 degrees down in the Sooner state with occasional thunderstorms and tornado's.

[chinewalk]

Yes sir! I had one 6.5 Grendel case mixed in with some used 7.62x39 cases I bought a while back and it converted quick and easy in one pull with my ARC sizer die. It has a different POI than the factory cases with my 1/2" load, but it sure converted easy. The 7.62x39s aren't proving to be that easy, at least for me.

[usbp379]

Hmmm. I go straight from 6.5G to 6G in one pass, but I don't push shoulders back. Annealing the neck of a few cases and try it again.
Usually this time of year its 100 degrees down in the Sooner state with occasional thunderstorms and tornado's.Again, the issue with 7.62x39 to 6 ARC is the case taper. Trying to work a new shoulder into the case that's essentially right on top of the taper is likely going to result in a buckled case. To make it work the brass must be incrementally worked down and/or the taper needs to be blown out via something like hydro forming.

Sent from my SM-G970U using Tapatalk

[chinewalk]

Again, the issue with 7.62x39 to 6 ARC is the case taper. Trying to work a new shoulder into the case that's essentially right on top of the taper is likely going to result in a buckled case. To make it work the brass must be incrementally worked down and/or the taper needs to be blown out via something like hydro forming.

Sent from my SM-G970U using Tapatalk

Agreed, more buckle than not with the tools that I have.

[usbp379]

Agreed, more buckle than not with the tools that I have.What about sizing and trimming just enough to get a casing to chamber? I imagine you'd be fractionally close to fully sized / cammed over at that point. But it might be just enough to keep from trying to push a new shoulder into the case taper.

Sent from my SM-G970U using Tapatalk

[chinewalk]

That might work, but I would be a little uncomfortable with doing it in an AR. I might just go buy another box of factory to get the brass. Thats what I did to get the ones I have, but they are getting pretty wore out now.

I appreciate all of the suggestions!

[usbp379]

That might work, but I would be a little uncomfortable with doing it in an AR. I might just go buy another box of factory to get the brass. Thats what I did to get the ones I have, but they are getting pretty wore out now.

I appreciate all of the suggestions!Any luck?

Sent from my SM-G970U using Tapatalk

[chinewalk]

Hey! Good morning!

Actually, no but I have been distracted with cleaning up the mess on the property after the flood that happened a while back. The property where my range is got hit hard and I had to spend some time on a tractor getting logs out of the way and building a road back. Then my neighbors road wound up in my four acre yard which looked like a gravel bar which I finally got cleaned up Wednesday. And now it is raining again.