6mm Arc brass

[USBP379]

First I've heard of that one; looks like a neat offering at a more easily digestible price point.

Price is fairly close to the Annealeez although the EP Integrations price includes shipping. It also comes with a torch head. I don't think the Annealeez price includes a torch or freight costs.

The EPI seems to work okay once you get the hang of it. It is pretty easy to get into a rhythm with the thing. One suggestion is to dump the annealed brass out of the catch tray often. That way a dropped case that falls into the catch tray is more easily identified and removed.

 

[USBP379]

I have now fire formed some previously new Starline brass. It went from 1.49" after sizing and initial trim to about 1.46" after fire forming. Interesting that is shrunk so much compared to my mixed headstamp range pickup stuff.

 

[USBP379]

https://www.americanrifleman.org/content/review-hornady-6mm-arc/

 

[USBP379]

Some weeks back I called Hornady and placed an order for a hydro form die kit. The kit includes two forming dies and the hydro die. Dies 1 and 2 size the case and the neck. The hydro die will be used to blow the taper out of the case and set the shoulder at its final location. After these three dies are used the case should be ready for one more size (standard 6 ARC sizing die) and then trim.

The Hornady kit is expensive but it should save money in the long run since I won't be wasting primers, powder and bullets to fire form. I could save a little money now by using what's known as the Cream of Wheat method but I'd still be wasting primers and powder. I guess the only way to make the kit pay for itself is by forming up a couple thousand pieces. I'll have to start scouring auction sites and brass retail sites for more 7.62x39 brass.

Anyway, I'm pretty excited to see how well the Hornady set works. I have a tracking number from Hornady this morning and will hopefully have the kit late this week. I'll post again once I've received the kit and had a chance to reshape some brass.

 

[Warpiece]

How much did it end up costing?

 

[USBP379]

How much did it end up costing?

The hydro die itself is $180. The step 1 and step 2 dies were extra. May or may not have been needed and I debated with myself about buying or just sticking with my RCBS .264 LBC die as the initial neck size die. In the end I decided to get the Hornady dies to--hopefully--keep from crushing the occasional case. I'm also hoping the Hornady dies won't be so aggressive on the case body and won't leave the "belted magnum" ring.

 

[USBP379]

Hydro die set received.

Slight correction to the above. Die 1 doesn't really do anything to the case, per se, but rather to the shoulder. It leaves the case at essentially 30 caliber but starts the initial shoulder on the case. Cases coming out of Die 1 look basically like a 7.62x39 version of the 300 BLK. A fairly long neck with no real definite shoulder between case and neck. Die 2 takes the new long neck and reduces it to 6mm. Then the last die, the hydro die, is used to blow the long leck into a shoulder and also to take "most" of the taper out of the case body.

I say most because previously loaded and fire formed AK-ARC brass are .430" just below the shoulder. The hydro cases measure about .426 at the same area. Cases that haven't been fire formed or hydro formed measure about .419 at this spot. Will the .004 have a radical impact on load development and case capacity? If so there isn't a whole lot of reason to hydro form if cases have to be loaded and shot before they're ready to be loaded and shot...

Anyway, the process itself is pretty straightforward. Slow but simple enough. Lube cases and run through Dies 1 and 2. Then fill with water and form. Dump water out and size to deprime and to give shoulder a final set. I did ~60 cases in maybe an hour and a half on a single stage. Not very fast but I'm probably not being very efficient. Things will likely go more quickly as I refine my process.

It should be entirely possible to set Dies 1 and 2 in something like a Lee Turret. On the turret it would also likely be easy to seat a spent primer in the event that new unused brass is being formed. Then switch to single stage to form. Hydro forming could likely also be done on the turret. Either way should be fine. Then fully size and deprime cases and give them a trim. As they come out of the forming process cases are all at 1.5+ inches. Tumble and load. Or wash and load whatever you prefer.

A couple random things; the primers sort of hydro decap and get wedged against the shell holder. It can take some wiggling and rocking to get them out. Not all cases are as nicely formed as others. A result of probably slightly different amounts of water coupled with not exactly the same amount of force from the hammer. A good sturdy 3-4 whacks seems to work well.

Anyway, my initial batch of cases is drying now. I'll probably trim them tomorrow and load over the weekend.

I need to post some pics, I suppose. And if anyone had questions let me know. Thanks.

 

[Warpiece]

You plan on measuring case capacity before and after?

Do you intend to anneal before or after firing?

 

[USBP379]

You plan on measuring case capacity before and after?

Do you intend to anneal before or after firing?

I was thinking about case capacity. I need to take the decapping pin out and size and trim to get an idea of what I'm working with.

I'll anneal before loading.

One other thing to add into the die assortment is a Lee universal flaring die. Anything that's got a dented case mouth will be run through to iron out the dent. Not to flare but to remove the dent as much as possible. There is a fine line between what the forming dies will iron out and what gets destroyed by the form process. Sometimes the dent turns into a deep crease that ruins the case mouth.

 

[USBP379]

The local hardware store has a bunch of 6 ARC ammo both in Match and Black loadings. This basically makes my form die efforts obsolete...

 

[Warpiece]

You can still get the 7.62x39 from starline at less than $100 for 250 pieces (cheaper than grendel brass), would be impressed if the factory ammo breaks down to anything close. Add in the large rifle primer option it gives you during a shortage, with potential accuracy benefits. I wouldn't consider it obsolete, certainly not right now, but I guess that's subjective.

 

[USBP379]

You can still get the 7.62x39 from starline at less than $100 for 250 pieces (cheaper than grendel brass), would be impressed if the factory ammo breaks down to anything close. Add in the large rifle primer option it gives you during a shortage, with potential accuracy benefits. I wouldn't consider it obsolete, certainly not right now, but I guess that's subjective.

Are there accuracy benefits to large primer? Some people are using SRP in stuff like 308 and 6.5 Creedmoor as they believe that is a key to accuracy.

I need to try a couple methods of seating for old primers in new brass. I tried seating a few with my Lee hand primer tool but they won't come out of the shell plate with an old primer in place.

 

[Warpiece]

I haven't seen it myself, don't really have the range available, but would love to test it.

Some people in the grendel community seemed to think something was there, making grendel brass from 7.62x39. Pure assumption on my part that it might translate over to the arc, if there is any truth to it to begin with

 

[USBP379]

I haven't seen it myself, don't really have the range available, but would love to test it.

Some people in the grendel community seemed to think something was there, making grendel brass from 7.62x39. Pure assumption on my part that it might translate over to the arc, if there is any truth to it to begin with

I do certainly agree that it gives good flexibility having a choice of L or S primers. Ideally a fellow would have something like 500 pieces of brass that will accept L and another 500 for small. Remington and Hornady make small pocket. Anyone else for 7.62?

 

[USBP379]

Here is a photo L to R of cases in the process.

L is a 7.62x39 as fired. Middle is after Die 1 with the shoulder moved back. R is Die 2 with the case necked to 6mm and a basic form.

 

[USBP379]

And L to R:

L out of Die 2

Middle water formed

R full length sized, trimmed, annealed

 

[USBP379]

 

[USBP379]

Been busy forming brass with my new dies. The process is pretty time consuming but it seems to get the job done. Not as fun as fire forming and the cases don't come out as "crisp" at the neck and shoulder angles. But I'm also not wasting gas or gunpowder.

I finally managed to get some Barnes match bullets and a couple cans of Leverevolution ordered through Midway. LVR appears to be one of the better powders for the 6 ARC so I'm curious to see how it might work with my new brass.

 

[USBP379]

Where we at with this project? Anyone else making ARC brass from 7.62x39?

 

[AJC1]

If I'm reading the situation correctly, buying loaded ammunition would be your cheapest easiest route. This is a complex decision based on many factors.
1. Most factories are focused on popular cartridges mostly NATO 9mm 308 and some hunting.
2. This is a new cartridge with very few pieces of brass in circulation.
3. Primers are a national issue.
4. Cases like 7.62×39 are now in high demand due to current import bands. People used to shooting steel are now looking to brass for long term to protect their intrest.
5. The amount of brass you shoot per outing is limited by other things and your normal stockpile of a 1k on hand should be adjusted to a much longer timeline. Have enough to shoot, stocking components later when things ease.

 

[FROGO207]

One thought. If you are having trouble with primers popping out some, get a feeler guage and slide it in under the brass. Make sure it is in beyond the center hole in the shell holder. The thicker the better. Form the brass, pull the feeler and remove the brass. This should keep the primer from moving out under pressure.

 

[USBP379]

If I'm reading the situation correctly, buying loaded ammunition would be your cheapest easiest route. This is a complex decision based on many factors.
1. Most factories are focused on popular cartridges mostly NATO 9mm 308 and some hunting.
2. This is a new cartridge with very few pieces of brass in circulation.
3. Primers are a national issue.
4. Cases like 7.62×39 are now in high demand due to current import bands. People used to shooting steel are now looking to brass for long term to protect their intrest.
5. The amount of brass you shoot per outing is limited by other things and your normal stockpile of a 1k on hand should be adjusted to a much longer timeline. Have enough to shoot, stocking components later when things ease.

Factory ammo is available but continues to hover around $1.50 per cartridge at its cheapest.

The simplest route to 6mm ARC, for the hand loader, is 6.5 Grendel brass. This requires a slight shoulder bump and a trim from 1.51" to 1.475." After that it is load as per usual.

Grendel brass isn't really hard to come by but inflated prices are a turn-off. 7.62x39 cases are also selling for more than they were a year ago but are still less expensive than Grendel stuff. Down side is most of the x39 brass is large primer. Or is this actually a good thing? Primers do continue to be hard to come by so having batches of brass for both large and small primers gives the hand loader some versatility in primer selection.

I've been buying 7.62x39 here and there for several months and haven't really noticed a spike in prices since the Russian ammo ban.

 

[USBP379]

Geissele has introduced a rifle chambered in 6 ARC although I don't know if any have shipped yet. Ballistic Advantage has reintroduced 6 ARC barrels; having previously dropped them in order to focus on backlogged 5.56 products. Stag Arms is also set to produce rifles as is CMMG.

None of these independently is a big deal but, hopefully, it means the industry is starting to see consumer interest in this cartridge. One thing still lacking seems to be another source for ammo. I'm actually surprised Starline or Peterson isn't making brass and that Federal or Winchester hasn't started making ammo.

In the meantime I won another small batch of mixed headstamp 7.62x39 brass off gunbroker.com. Time to break out the Hornady form dies.

 

[Varminterror]

Brass and ammo are coming around. I made some of my “second batch” of 6 ARC from Grendel brass, but I don’t think I will any longer, or again. I still use Grendel brass as is, and still have a 243LBC going on Grendel brass, and it’s been easy enough to source once fired 6 ARC brass, I simply don’t want to bother with case forming.

 

[USBP379]

Brass and ammo are coming around.

I haven't had any luck finding 6 ARC brass either new Hornady or range brass. There have been a few batches on gunbroker.com but they've sold for very close to price of loaded ammo.

We did have a local shop that received a pretty good batch of Hornady ammo. Price was about $1.75 per cartridge. I bought a few boxes just to buy it.