6mm arc?
- Thread starter Shadow9mm
- Start date
jetinteriorguy
New member
Interesting, I haven’t had this happen with any of the .223 I’ve fired using the goat. I’ll have to try it with 7.62x39 to see if that will ding the necks.
stagpanther
New member
Why are other better 6mm's not seen in AR's? Because they're likely a pain to get to cycle and feed properly. Getting cartridges to seat and feed from semi-auto magazines can be the make-or-break deals. The ARC--along with the 6.8 spc version (ARP has one called the 6mm Predator)--are based on proven cartridge designs that work reliably (though my personal experience with cats from both the grendel and 6.8 spc has been the 6.8 spc has an edge in reliability). 6.8 spc also has an advantage in a more straight-forward bolt/carrier topology having avoided the type 1 vs 2 and thin wall vs superbolt wars.
The dinged case mouth is not uncommon--that can happen upon ejection when the spent case pivots backwards and the mouth hits the deflector on the upper. I cut a triangle of the fuzzy stuff in velcro and attach it to the deflector and usually that solves that problem.
The dinged case mouth is not uncommon--that can happen upon ejection when the spent case pivots backwards and the mouth hits the deflector on the upper. I cut a triangle of the fuzzy stuff in velcro and attach it to the deflector and usually that solves that problem.
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So..... Starline just added 6mm arc to their lineup. Of course its out of stock on backorder, but that's a good sign! Its not premium brass, but its good quality.
https://www.starlinebrass.com/6mm-arc-brass
https://www.starlinebrass.com/6mm-arc-brass
stagpanther
New member
I've never had ARC brass or dies since it first came out--I just use starline's grendel brass and neck it down. I had to buy a grendel bushing sizing cause no ARC dies were out when I first jumped on the bandwagon. It's an easy to reload for cartridge--even if you have to improvise. The one thing I'd recommend you look for is a PRI magazine with the front cut-out so you can seat those long bullets long; some of them look like they could reach all the way down the case and hit the top of the case head web when seated to 2.26.
I've shot tons of starline and Hornady grendel brass--I prefer starline's.
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stagpanther
New member
To shadow--I had something of a brain fart when I compared the 6mm ARC to ARP's 6mm Predator--I had forgotten that Harrison had actually developed his cartridge (using the grendel case as parent) a couple years or so before the ARC came out. I have AR builds for both--AFAICT the ARC differs only in the shoulder being set back by a few thousandths of an inch. Neither case is very long and both can seat bullets fairly long when using a magazine that allows going beyond 2.26. Harrison had actually used Hornady to make dies for his 6mm Predator--and then Hornady rolled out the ARC. That few thousandths of an inch does make something of an impact on case capacity, though.
Very interesting!
stagpanther
New member
I felt a bit silly in not readily recalling the load formulas I had used for the 6mm ARC--but then stumbled across my data for the 6mm predator and realized it is almost the same as the ARC except that it affords a bit more powder capacity--like the original grendel. Anyway, I had some really good results in the predator using 8208 XBR and I have a hunch (hope) that it works equally well in the ARC.
I was going to put together an ARC but came into a good deal on a complete rifle chambered for the 6mm Grendel. Love it, very accurate, functions perfectly. I load it using ARC dies set out a ways just bumping the shoulder of the case formed from Grendel brass. I like the fact that getting Grendel brass is not an issue. Sure the 243 gets 2-300 fps more, so what? Both are deer capable rounds better for that job than the 223.