6mm arc vs 6mm max

[mevert]

Wanting to start a discussion to help me decide between a 6mm max or 6mm arc. Looking at around the 12 inch barrel mark for a compact ar15 coyote gun. Thanks for any input!

 

[UnckleBob]

6 ARC is starting to get more and more factory anmmo options.

Is the extra performance of the Max worth the hassle?

 

[mevert]

6 ARC is starting to get more and more factory anmmo options.

Is the extra performance of the Max worth the hassle?

You are probably right. The more I look into it I am not sure i would be able to form brass myself either for 6 max.

 

[Rich M]

Another 6mm bullet? Max?

Exciting times for sure.

 

[WestMOhunter]

I was hoping this would get more traction. I have been trying to decide on another AR cartridge. Kicking around 22 and 6 ARC in a 16”, then 6 Max enters the chat. I like the idea of standard bolt face, but not sure it’s 95 TMK capable. Anyone know?

 

[KyleR1985]

I was hoping this would get more traction. I have been trying to decide on another AR cartridge. Kicking around 22 and 6 ARC in a 16”, then 6 Max enters the chat. I like the idea of standard bolt face, but not sure it’s 95 TMK capable. Anyone know?

.590” of a 95tmk will be inside the case of a 6mm max cartridge at 2.30 COAL.

Not sure what 95tmk capable means. But if you mean optimal, I don’t think that the max will be more optimized for the long bullets in AR mag constraints than the 6ARC.

It’s a guess because I don’t have a 6max case in front of me, but I bet actual powder capacity at 2.3” OAL with long bullets (95-108 class) is equal or very close to 6ARC.


If you want to make the argument for the cartridge, it would be building on a bolt action .378 bolt face and wanting max capacity for 6mm bullets. This is ignoring the logistics, which are complex.

 

[WestMOhunter]

.590” of a 95tmk will be inside the case of a 6mm max cartridge at 2.30 COAL.

Not sure what 95tmk capable means. But if you mean optimal, I don’t think that the max will be more optimized for the long bullets in AR mag constraints than the 6ARC.

It’s a guess because I don’t have a 6max case in front of me, but I bet actual powder capacity at 2.3” OAL with long bullets (95-108 class) is equal or very close to 6ARC.


If you want to make the argument for the cartridge, it would be building on a bolt action .378 bolt face and wanting max capacity for 6mm bullets. This is ignoring the logistics, which are complex.

Yeah, I believe everything you’re stating here is correct and pretty much what I thought. The cartridge is intriguing if you don’t care about shooting 108 ELDM (I don’t) and like the idea of a standard bolt face (I do). I’d be happy with 65-75 Vmax on coyotes and 95 TMKs on deer, etc. It definitely isn’t optimal, but I suspect the bearing surface of the bullet is going to lose contact at the case mouth due to long ogive - not “capable.” Just thought maybe someone could verify. I’ll likely go with a Core Criterion in 6 ARC. It’s the easy button, but I don’t always use it. Ha. Appreciate the feedback.

 

[Gtscotty]

.590” of a 95tmk will be inside the case of a 6mm max cartridge at 2.30 COAL.

Not sure what 95tmk capable means. But if you mean optimal, I don’t think that the max will be more optimized for the long bullets in AR mag constraints than the 6ARC.

It’s a guess because I don’t have a 6max case in front of me, but I bet actual powder capacity at 2.3” OAL with long bullets (95-108 class) is equal or very close to 6ARC.


If you want to make the argument for the cartridge, it would be building on a bolt action .378 bolt face and wanting max capacity for 6mm bullets. This is ignoring the logistics, which are complex.

6 Max always seemed like a throwback to 90s cartridge design to me, I was surprised when it got any traction. Most modern cartridge designs have followed a similar pattern as the Creedmoors, shorter, less tapered case design to get the heavier bullets they were designed around out of the case at mag length. The ARCs follow that pattern as well, but the 6 MAX is kind of an update of the old 6x45 with many of the same limitations shooting heavier bullets.

If you're concerned about bolts and mags I'd recommend getting Rexus bolts and G$$ mags. They aren't really expensive, and work great with the increasingly common and popular ARC series.

 

[WestMOhunter]

6 Max always seemed like a throwback to 90s cartridge design to me, I was surprised when it got any traction. Most modern cartridge designs have followed a similar pattern as the Creedmoors, shorter, less tapered case design to get the heavier bullets they were designed around out of the case at mag length. The ARCs follow that pattern as well, but the 6 MAX is kind of an update of the old 6x45 with many of the same limitations shooting heavier bullets.

If you're concerned about bolts and mags I'd recommend getting Rexus bolts and G$$ mags. They aren't really expensive, and work great with the increasingly common and popular ARC series.

I’m not concerned. I’ve had excellent results with 3 E-lander 10-round mags in 6.5G. Out of the 5 C-Products mags I’ve had, only 1 had an issue and a feedlip adj. fixed it. I’ve thought about buying a JP, but I’ve never had an issue with any of the Toolcraft Grendel (.136”) bolts, so I’ve not spent the $ on the high end options. Maybe some on here can relate to the “worst-case senario” thinking that I occasionally suffer from. In reality, the 6 ARC is almost certainly the right answer. Now I’m just wavering b/n 6 and 22, but since I’m set on 16” still leaning 6 ARC. Thanks for the thoughts.

And sorry, I just edited… realized you weren’t really replying to my comment but still appreciate the info.

 

[Gtscotty]

Yeah, I believe everything you’re stating here is correct and pretty much what I thought. The cartridge is intriguing if you don’t care about shooting 108 ELDM (I don’t) and like the idea of a standard bolt face (I do). I’d be happy with 65-75 Vmax on coyotes and 95 TMKs on deer, etc. It definitely isn’t optimal, but I suspect the bearing surface of the bullet is going to lose contact at the case mouth due to long ogive - not “capable.” Just thought maybe someone could verify. I’ll likely go with a Core Criterion in 6 ARC. It’s the easy button, but I don’t always use it. Ha. Appreciate the feedback.

Just to clarify, it's not just the 108gr that's going to work better from the shorter cases, it's a lot of the modern bullets most folks are looking to use. In my rifles, the 103gr ELDx hit the lands at around the same OAL as the 108gr ELD, but the 107gr TMK, 100gr TGK and 90gr TGK are all longer OAL at the lands. A lot of the older bullets (95gr SST) and the light end of the bullet range (80gr CX, 85gr GK, etc) should be fine for the 6 MAX, but the ARC can handle pretty much any weight well and match or exceed 6 MAX velocities, so I've just never really seen the value proposition of the MAX. I don't know for sure about the 95gr TMK, but based on my experience with Sierra's other newer 6mm bullets, I'd guess it's going to be too long to really work well in the MAX case, at the very least you're going to have a long jump and a lot of bullet taking up powder capacity.

I'm all for folks getting what they want, but the 6 MAX does seem like an odd reversion from the mean for modern cartridge design and I don't really get the draw, it reminds me of all the .260 vs 6.5 CM discussions that went on when the Creedmoor first came to market, but backwards.

If someone is really concerned about ARC bolts and magazines (the only possible advantage to the MAX I can see), they might my be interested in building an ARC using PSA's new ICAR compatible receiver sets.

https://palmettostatearmory.com/sabre-ic-ambi-receiver-set-moss-green.html

These sets are compatible with the Magpul ICAR mag (and only that mag currently), will be compatible with the larger E4 barrel extension/bolt that's coming out for the ICAR, but, importantly are also backwards compatible with mil spec barrel extensions and regular ARC/Grendel bolts. This is kind of the proverbial AR-14, as long as you're good using the Magpul 25rd mags, you can build a rifle using the ARC barrels and bolts that are out there now, and then when the stronger E4 bolts come out you can swap to a new barrel if you want and potentially shoot bolt gun pressure loads.