• This Forum is for adults 18 years of age or over. By continuing to use this Forum you are confirming that you are 18 or older. No content shall be viewed by any person under 18 in California.

6mm ARC v's 6mm ppc

Wikipedia says that the length of a ppc is 1,515 and the rim is .445 and ARC length is 1.490 and rim is ,441 that is the ARC is .025 shorter . So basely the same case . Right ?
 
Wikipedia says that the length of a ppc is 1,515 and the rim is .445 and ARC length is 1.490 and rim is ,441 that is the ARC is .025 shorter . So basely the same case . Right ?
Art, it appears wiki is using case oal rather than the headspace to datum. And in order to compare apples to apples, we need to look at saami chamber specs. Now, that gets even more complicated by the fact that a PPC is not saami approved so doesn't offer drawings to compare. It's a wildcat and can technically be just about anything. But for simplicity's sake, I have a "standard" ppc reamer print that shows hs dimension to the .350 datum point of the shoulder to be 1.1451. (FWIW, I also have prints that call for a .330 datum! Effectively the same but measured from different datum lines. Go figure.)
Saami 6arc to the same .350 datum is 1.1901. So, the 6 ARC is .045 LONGER to the same point than a 6 PPC.
To complicate things a bit further, the 22 ARC is longer than either of them @ 1.2201, exactly the same as a 6.5 Grendel.

So, a 6 ARC is .045 longer than a ppc and a 22 ARC is .075 longer than a PPC.

You are correct in saying the difference in capacity of a 6PPC and a 6 ARC is negligible but the oal wiki gave you isn't really relative nor set in stone. I have ppc prints for different oal dimensions! Remember, it's a wildcat, so neither is right or wrong, but are different. And I've seen others dimensions for oal with them. It amounts to trim length for YOUR PPC chamber.

You can look up saami cartridge and chamber specs here but a PPC being a wildcat, you'll have to source it elsewhere. Just remember to compare chamber specs to chamber specs, not chamber to cartridge.

Below is a ppc case and calipers set .045 longer...for a visual.
1746457534349.png
 
Last edited:
So to the other question in your original post, yes you can make it. But with Alpha making both offerings, the easy button would be to buy the Alpha 6ppc. The Peterson ARC brass is pretty darn good stuff too. JME. WD
Thanks WD. I didn't respond to that part of his question because I haven't tried to push arc brass back that far. I have made 6 Grendel brass from 220 r brass though. It'll work that direction but the best I've been able to get is still about .016 shorter than my trim to length. It shoots fine as long as I stay on top of the carbon ring, though.

That said, 6 arc brass might fire form fine in a 6 Grendel. If the quality is there, it could be another option, as would be pushing the shoulders back the .045 for a ppc. Truthfully, I've got plenty of Lapua grendel brass and it's just the easy button for a 6 or 22 grendel(arc) case. The quality is just as good as 220r brass is for a ppc, IME.
 

Upgrades & Donations

This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.


Click Upgrade Membership Button ABOVE to get Gold or Silver Status.

You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.


To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.

Forum statistics

Threads
164,776
Messages
2,184,217
Members
78,524
Latest member
SJTUTTLE18
Back
Top