6MM ARC caliber

[Charlie1022]

I see where Hornady just announced a new caliber that looks very interesting that will work in an AR 15. It looks interesting on the videos for anyone wanting more down range out of their AR 15 without jumping up to the AR 10. Very low recoil also adds to my interest. Anyone have one yet and what are your thoughts?

 

[horsemen61]

I’m interested for sure but in a cute lil cz 527 now that I could get behind

 

[troy fairweather]

When I have money I'll put one together. I've been waiting all year for it to come out. Early reports are looking good.

 

[CarJunkieLS1]

Granted it's a different company but I jumped on the 224 Valkyrie train as soon as it released and I've been pretty disappointed...so I think I'll wait a while before I look at the 6 ARC.

 

[horsemen61]

Granted it's a different company but I jumped on the 224 Valkyrie train as soon as it released and I've been pretty disappointed...so I think I'll wait a while before I look at the 6 ARC.

Big difference in this and Federal mucking up the .224 Valkyrie by rushing it to the market

Hornady has done very well with their recent cartridges they’ve rolled out ie the hottest cartridge to hit scene since ........ever in the 6.5 Creedmoor

I think they did the legwork with this one and didn’t leave it DOA as federal did with the Valk .... that’s just my thoughts though ymmv

 

[montanaoffroader]

I'm keeping an eye on it as well. It looks good on paper, if it works in the real world I might consider it for my next build.

 

[Poper]

It appears the a US military organization has adopted this cartridge: https://www.gunsandammo.com/editorial/hornady-6mm-arc/376852
Doesn't say if Army, Marines, Seals, Green Berets or what other.
Must have been quite the trials to get gov't approvals, tho.

 

[CapnMac]

On paper, at least, the 6arc is everything that the 5.56x45 is not.
A weighty, good BC projo, and a useful balance of weight, case size, and OAL.

A person could make an excellent argument that Stoner and Sullivan would have selected 6arc over the sort-of wildcat .223 Maybe. Perhaps.

Would pair well with the new 7x51 for the new SAW in military operations.

Will be interesting to see which barrel twist will be best with 6arc.

 

[rdnktrkr]

I have a couple of extra lowers and wouldn't mind trying one as a 6ARC, I've been looking for something to go with my Grendels, but I think I will let the hoopla go away and the bugs worked out before jumping in.

 

[.455_Hunter]

The thin bolt head gives me pause. I might have liked a 6mm on the 6.8SPC case better.

 

[Varminterror]

The thin bolt head gives me pause. I might have liked a 6mm on the 6.8SPC case better.

Read the other thread linked above. The skinny SPC case is pretty lackluster when it is shortened sufficiently to fit into an AR mag with 105+ grain bullets with .7”+ ogive lengths.

 

[Varminterror]

Will be interesting to see which barrel twist will be best with 6arc.

1:7”-1:8” will do well with the 105-110grn bullets in the 6mm ARC.

 

[.455_Hunter]

Sorry- I have to laugh a bit...

The new hotness 6mm ARC, with a 108 gr bullet @ 2750 fps (24 in barrel, less from a sub-16 in barrel) almost exactly duplicates the 6mm Lee, adopted by the Navy only 125 years ago, featuring a 112 gr bullet at 2550 fps from the 1895 Lee Straight Pull rifle.

The more things change, the more they stay the same. There really isn't much of anything new under the ballistics sun.

 

[Varminterror]

@.455_Hunter - how many AR-15’s have been sold in the last 125 years chambered in 6mm Lee?

Cars still drive, as did the Benz Motowagen. But you’d struggle to sell a car today which steered with a tiller.

 

[.455_Hunter]

@.455_Hunter - how many AR-15’s have been sold in the last 125 years chambered in 6mm Lee?

None- But it's still damn hillarious that the ballistics are the same.

Just like the factory 180 gr JSP 350 Legend has the same performance as the 180 gr JSP .351 Winchester.

 

[Varminterror]

If a specific combination of ballistic metrics worked well in one platform, there’s simple logic in continuing to make use of similar ballistics in another. Nothing terribly comical about it. Wheels work under trucks, cars, and motorcycles... they also work under roller skates, bicycles, and skateboards. Wheels even work under trains and airplanes...

 

[.455_Hunter]

Nothing terribly comical about it.

I guess when you are a military firearms history nut, a prior Active Duty Army Officer, and closing in on twenty years as a research engineer with emphases on energetic materials and weapon system ballistics, its more of an inside joke.

If a specific combination of ballistic metrics worked well in one platform, there’s simple logic in continuing to make use of similar ballistics in another.

The key word there is "continuing". The US military has not used a cartridge with these performance parameters since the 1895 Lee's were phased out of combat service by 1907, over a century ago. A better example of continuing would be the use of a .308 inch diameter spritzer bullet, weighing ~150 grains, and fired at ~2700 fps- that combo has been on daily duty since 1906.

Wheels work under trucks, cars, and motorcycles... they also work under roller skates, bicycles, and skateboards. Wheels even work under trains and airplanes.

An overly generalized analogy that ignores the highly specific aspects of US military service, bore size, projectile weight and velocity in this discussion.

 

[briansmithwins]

Every review board that did studies of optimum rifle cartridge calibers has come back with something in the 6.5mm/.250 range, +/- ~0.5mm. Events have intervened to stop actual adoption by the major military powers in the 20th century.

BSW

 

[.455_Hunter]

Every review board that did studies of optimum rifle cartridge calibers has come back with something in the 6.5mm/.250 range, +/- ~0.5mm. Events have intervened to stop actual adoption by the major military powers in the 20th century.

BSW

Yup- Rounds like .276 Pederson and the .280 British have very interesting and scandalous histories.

 

[rbernie]

Every review board that did studies of optimum rifle cartridge calibers has come back with something in the 6.5mm/.250 range, +/- ~0.5mm.

257 Roberts, FTW!

 

[briansmithwins]

Yup- Rounds like .276 Pederson and the .280 British have very interesting and scandalous histories.

I expect we’ll see military adoption of a ~6.5mm caliber round only in combination with a new case technology, such as telescoped case that opens up possibilities for more efficient feed mechanics and weight savings.

A generic 6.5mm caliber round wouldn’t be enough alone to get anyone to switch if it’s still fired about of a steel or brass case. But the ability to have one standard ammunition for your rifles and GPMGs* and that ammo takes ~50% of the logistics to supply? That starts too look appealing if you’re equipping and supplying an army.

The metallic cartridge case is what, 150 years old? It’s time we got something better.

BSW

*Plus, because your cartridge is shorter and maybe doesn’t need a extraction stroke, the weapons that fire it can be smaller & lighter too.

 

[Walkalong]

Still seems like a cool new caliber to me, despite any ballistic emulations of Christmas past.

It will stand or fall on its own merits. May very well catch on with the AR crowd, maybe even the bolt crowd, especially in an mini action.

 

[troy fairweather]

From what I've seen the numbers look good, tho I don't much care of it's better the the grendel or others. I've had a long time liking of the 6mm-222 great all around cartridge, harder to find rifles anymore in 6-222 so I'm all for a more powerful modern cartridge to hold me over.

trying to find a sako L46 may have to use a cz.

 

[CapnMac]

I expect we’ll see military adoption of a ~6.5mm caliber round only in combination with a new case technology, such as telescoped case that opens up possibilities for more efficient feed mechanics and weight savings.

Yep. But, I'll bet it will be an even value--either 6mm or 7mm even. 7x45 might be an interesting area.

 

[George P]

Sorry- I have to laugh a bit...

The new hotness 6mm ARC, with a 108 gr bullet @ 2750 fps (24 in barrel, less from a sub-16 in barrel) almost exactly duplicates the 6mm Lee, adopted by the Navy only 125 years ago, featuring a 112 gr bullet at 2550 fps from the 1895 Lee Straight Pull rifle.

The more things change, the more they stay the same. There really isn't much of anything new under the ballistics sun.

Also seems to be somewhat related to the older Remington 6mmBR class