Data is out already showing 2450 from a 14.5” barrel. Not bad speed at all for an SBR, cannot complain about a 14.5” rifle with a transonic boundary past 1,000yrds.

That's swell and dandy but I see no particular military application for that. This is a round that was developed for/by DoD.

M855A1 is traveling at 3000fps from the same barrel length. In the thinking of the military M855A1 is already insufficient in armor penetration, which is why the Army and Marines have the NGSW program and these super hotrodded unicorn 85k PSI 6.8mm rounds competing. What is the point of a 2450fps cartridge from a 14.5" barrel in any kind of a military context?

None that I can think of.

If this is in some way slightly better than some existing cartridge in some niche hunting role or something, that's great. I see it's military value as somewhere slightly north of zero.

what would a 30rd ar15 5.56 mag hold in 6mm arc? single stack? 10-15?

seems appealing for an ar15 setup

in a bolt gun, not sure I see the appeal.


found my own answer....supposedly a 30rd ar15 5.56 would hold about 25 6mm arc.

Yes 25rds, same as the largely defunct 6.8mm SPC.

Guess it’s a good thing the DoD didn’t ask your opinion, since they obviously had an application for the 6mm ARC.

I wonder what would even make you hit your reply button and type that.

Is it ok with you if we discuss the merits of this cartridge in a military context? Your comment is entirely unhelpful...you did not even begin to offer any kind of information or debate, just a snooty remark.

What is it that you (or anyone) foresees this doing in a military context that existing cartridges do not do? Outside of being cheerfully accepted by a few guys at Camp Perry, I see none.

But I'm just a former Mechanized Infantryman, so what do I know.

If you can’t understand any potential military applicable advantage of firing nearly twice the bullet mass with considerably higher sectional density (.25 vs .18) and twice the ballistic coefficient, which reaches 600 yards with 400fps greater velocity and 3 times the energy than M855, I don’t expect we can have a fruitful discussion.

What we do know - the DoD asked for this type of performance and such was delivered. So someone with a much more important opinion on the matter than you or I sees value in it. Barrett has begun delivering 18” Rec7’s with Proof Research match grade barrels to the DoD, so I think it’s reasonable to speculate your average infantryman isn’t going to be handling them - it’s obvious this isn’t a replacement for the M4.

I understand it will have significantly more recoil, and the magazines will hold 5 less rounds, thereby meaning an individual soldiers load out will be 35rds smaller. I understand the ammunition will also be significantly heavier.

I further understand that introducing a new cartridge will complicate logistics and supply chains.

In a military context these things matter far, far more than the ballistic coefficient of a projectile.

There are squad designated marksmen in every US squad, so this is potentially very relevant even at the infantry squad level.

Also, the US Army NGSW program calls for super hotrodded cartridges that push the envelope of technical viability (Sigs 6.8mm 85k psi round being a prime example- I believe the civilian designation is .277 Fury). Is this a fall back position if the NGSW fails? Does the military see it as a potential re-chambering for 7.62mm M240 machine guns? These are all 100% viable questions, and they are all directly relevant to the infantry.

Or is this a new sniper round. In which case, why are we even comparing it to 5.56mm ballistics at all? In that case the proper rounds to compare it to are 6.5 bleedmore, 7.62mm NATO and .300 win mag, all of which the military is currently using in that role.

As far as important opinions, the DoD asks for all kinds of, quite honestly, idiotic things. At great tax payer expense. Which is another valid reason to question this round, considering that we are in the middle of an economic melt down and the Pentagon is sure to see greatly reduced budgets next year. And we are all tax payers here.

Finally, I would say the bottom line of a discussion forum is to discuss things. Not for one dominant grouchy old buck to try to shut down conversation, for reasons known only to him. I am pretty sure that is not how any of this is supposed to work.

Also, what role would you or anyone else see this round filling from a hunting perspective? What does it do new, that some existing round is not already doing?

The DoD is far and wide compared to the limited scope most people complain about in rants about logistics. Various groups have been making use of a great number of cartridges for a long time, which has had absolutely nothing to do with the typical infantryman.

But the origin is what it is - the DoD asked, Hornady answered, and luckily for us consumers, a great little cartridge with almost almost 20yrs of wildcatting behind it - arguably nearly 50 years - is finally available in a low cost, factory offered form.

What are the cartridges that DoD Has been using for a long time that have nothing to do with the infantry? The only one I can think of off the top of my head is HK 4.6x30mm, which the USN uses in a suppressed role for sentry elimination (allegedly, even if it does seem a very peculiar choice)

One thing I think we need to consider from a military context is that if an EPR style penetrator projectile is used, maximum projectile weight will be in the area of about 85 grains.

I am interested to know what you think the ideal civilian hunting applications are. Seems like it would be pretty good for people who want to hunt big game (mule deer, etc) at longer ranges with an AR15 style platform. I think it has more promise as a civilian round, to be honest.