Copper Creek has modified cases

[grayfox]

Copper Creek has modified 6mm ARC cases for the hornady bullet OAL.
$9.00, well, plus shipping.
But so far nobody else has them.

[Dino11]

Copper Creek has modified 6mm ARC cases for the hornady bullet OAL.
$9.00, well, plus shipping.
But so far nobody else has them.

Do you have a link for them, my Google search comes up with nothing.

[Biodsl]

Copper Creek

https://coppercreekcartridgeco.com/produ...ied-cases/

[grayfox]

Case is arriving this morning, I will do some OAL measurements...

[skyrep]

mine is to arrive today also.

[grayfox]

Received my copper creek modified case.
Now my resized cases measure 1.184-5" at the datum line.
The modified case, 1.182. Its OAL is 1.483.

I took 3 bullets at random out of my boxes, of the following:
90 TGK
95 SST
103 Eldx
Hdy 105 Bthp
Sierra 100 BTSP (gameking)

Bullet COAL's were consistent, with the 100 SGK differing by 0.005... 'course it has a soft lead tip and I have found these usually differing in COAL by as much as +/- 0.005
Measured OAL's, modified case and bullet to the lands, for them in my chamber are as follows.

90 TGK: 2.338
95 Sst: 2.203
103 Eldx: 2.3005
105 Bthp (this is the one in the Hdy Black): 2.277
100 SGK: 2.140

For the 2 relative "shorties" I'll probably shorten my max OAL by 0.020, 95 Sst, 2.180; 100 SGK: 2.120.

The others will be limited basically by the mag, although I guess the 105 could go to 2.277, I'll keep it to 2.260 max.

But that's a huge delta from hornady's 105/ammo, they call for 2.200....
go figure.

[GrendelHunter]

Who made your barrel? Inquiring minds want to know.

[Dino11]

That 2.200 is for their 105 bullet profile, I load my Nosler's to 2.220 to 2.225 and that is giving me a .030 bullet jump. That 105 Hornady  needs redesigned. The Noslers have a better BC of 571 and they just shoot well out of my gun, it has become my bullet of choice thus far.

But I need to work up loads for some of the other bullets I have.

I got a new reloading toy, a Frankford Arsenal Intellidropper. This thing is really nice, and it's pretty fast too. It came 4 days ago but my son didn't tell me until this morning.

I had some doubts about the accuracy of my old scale, My FPS seemed to be dropping off, come to find out it was weighing 1.2 grains heavy which meant my loads were light.

[grayfox]

Who made your barrel? Inquiring minds want to know.

It's a Faxon, 20"... from Brownells.

Those 105's I have are the Hornadys.   This barrel has lots of head-space room for a normal 2.260 cartridge with them.  

I might get some Rdf's or even look at the Sierra 107's once I get around to them.  But if the 105's will load and shoot ok... well, I already have them on hand.

---

Dino... get some check weights, not a huge cost but gives you a check-calibration to bounce your scales against.
I use a combo that's close to my typical 30-50 gr's weight so I can look at apples to apples.

[Dino11]

I have check weights, and it came with some. They are the two silver things above the pan. This thing hits the numbers exact every time. Checked it with my beam scale and it is right on the money, just hate using the beam scale, it's a PITA. Loading 29.5 to 30 grains take about 10 seconds, and it learns how to drop your powder. If you switch say from Lever to Vargent, it goes through a learning process to find the best speed to drop your new powder.

I was having to recalbrate my old scale way to much, and I have had it a while. This new one makes short work of the task..

I know my picture sucks, I think the camera lens was dirty.

[skyrep]

Grayfox,
which gauge did you use to measure the Datum on you Cooper Creek Modified Case. Did you use the Hornady or the Forster.
I have a Forster and my case measured 1.185. the OAL is same as your measured.

[Dino11]

Grayfox,
which gauge did you use to measure the Datum on you Cooper Creek Modified Case.  Did you use the Hornady or the Forster.
I have a Forster and my case measured 1.185.  the OAL is same as your measured.

Those are the same numbers I am seeing, 1.183-1.185, I use the Hornady guage.

Those are the numbers for factory ammo and my full length resized as well. I am going to try and bump the shoulder less next time I reload and see if it cycles. My fired brass is measuring 1.190-1.191. I really only want to bump it .002-.003, I've been bumping .007, way to much for my liking.

Ideally you want to use a modified case that has been fired in your chamber. You can make your own gauge, but you need a specialized tap. It is a 5/16X34 and a #7 drill bit

[skyrep]

Grayfox,
which gauge did you use to measure the Datum on you Cooper Creek Modified Case.  Did you use the Hornady or the Forster.
I have a Forster and my case measured 1.185.  the OAL is same as your measured.

Those are the same numbers I am seeing, 1.183-1.185, I use the Hornady guage.

Those are the numbers for factory ammo and my full length resized as well. I am going to try and bump the shoulder less next time I reload and see if it cycles.

my fired cases have been measuring 1.194-1.195 (measured with the forster guage).  i'm bumping the shoulder back to 1.191 using the Wilson Bushing FL sizing die.  I have a Uintah Precision Bolt Action Upper on an Anderson Lower.

[Dino11]

As near as I can figure comparing my Odin barrel to 2 other Faxon barrels I have my chamber is about .006 tight. So your numbers come real close to actually comparing to an outside source. But damn it shoots good.

I really like your rifle, and I plan to order one of their uppers real soon. Just got to slow down a bit right now as I have been refitting my reloading bench and got a lot of monies tied up in these 6mm ARC's right now. I have not had this much fun shooting a rifle ever, I really enjoy this one. It's been some what challenging, But I enjoy the challenge.

How's that thing shoot? I know I'm going to have an ARC in bolt action real soon. I just hope the price and availability change after the election. But you never know I just may bite the bullet and get it anyways. My son keeps telling me to do it, he went out the other day and bought a .223 bolt action Savage. Only because I have been talking about getting the bolt action ARC.

[grayfox]

I like savages because they are easy to tinker with, but when I tried to build a Savage 10 in Grendel I had trouble getting it to feed reliably, with the dbm. Even though there is a 7.62-39 mag... finally sold the barrel instead. I think a couple of guys on Grendel forum got a 700-based Grendel but they didn’t talk much about what it took to get it to feed reliably. One of them is in Sweden or Norway...

[skyrep]

I'm having my Savage 10 (6.5 Creedmoor) being re-barreled to the 6mm ARC. Hoping to have it back in 6-8 weeks. Will see how it turns out. Had to find a PPC Bolt face to change it over.