White Oak Armament's thoughts on 6mm ARC
- Thread starter LVLAaron
- Start date
LVLAaron
Gold $$ Contributor
Parent case is a 220 Russian. Lapua is readily available... and make Sako?
Typical Copy Cat Technology. AR's have seen a Lack of innovative idea's. Shoot, even I can come up with a design around this problem. It's takes a Modified Barrel to allow for a larger Diameter Lug Face. This in turn would most likely require a modified Upper receiver. This could in fact be made to use the existing Bolt Carrier Group parts while allowing the Modified Bolt enough room for the extra Meat it requires for strength in the .450" boltface Sizing. I really would like to get Lapumo Muskets off the ground some day. Cheers!
effendude
Gold $$ Contributor
Makes perfect sense to me. You're a genius! Call the AR manufacturers and tell them how they are doing it wrong.
Scott
I would assume that if Hornady has developed a military adopted case they will have to have a mil spec brass. Does not make sense that the civilian market would get different bras but they might.
3 governing properties for velocity, pressure, case capacity and expansion ratio. However efficiency is another thing, case shape and projectile weight plays a major roll.Tell that to my 6mm Rem...My 6XC is faster with 10 gr less powder.
My best example of a rifle I have is the 358 Norma Magnum. In a 28" barrel with 250 graing projectiles I can match 358 STA velocities. Up the projectile weight and a velocity gap appears, the Norma being more efficientvwith 250's does not have the case capacity for heavier projectiles.
We may see a couple things the ARC does well, but due to a lack of capacity, long barrel, high pressure head to head comparisons with the 243, 6mm Remington or the 6mm XC is a not one of them.
My two thoughts:
1) I'm sure they'll tell you differently, but WOA has a stake in this ballgame. It's the 6WOA, accessories, development, and branding that went along with that.
2) Why don't you hear more often about broken lugs/bolts with 6.5 Grendel, 6mmAR, 22 Grendel, etc if it's that big of a problem?
1) I'm sure they'll tell you differently, but WOA has a stake in this ballgame. It's the 6WOA, accessories, development, and branding that went along with that.
2) Why don't you hear more often about broken lugs/bolts with 6.5 Grendel, 6mmAR, 22 Grendel, etc if it's that big of a problem?
Hoser
Gold $$ Contributor
I have been shooting a 6 Grendel for years. Mainly pushing a 105 to around 2,600 out of a 22 inch barrel. No broken bolts and incredible accuracy.
This is 5 shots at 600 yards with Berger Hybrids, Varget, Lapua brass and CCI primers. I have since switched to H4895 and accuracy is still there, but with less pressure.
This is 5 shots at 600 yards with Berger Hybrids, Varget, Lapua brass and CCI primers. I have since switched to H4895 and accuracy is still there, but with less pressure.
Except for it being SAAMI spec with factory ammo....
And adopted by the military.
best coyote round ever. 65gr vmax at 3400 fpsHoser
Gold $$ Contributor
Just because a very small segment of the military has bough a couple pallets of ammo doesent mean every dude will be carrying am M4 chambered in this caliber.
Lot of Tier 1 units can buy just about whatever suits their mission. That qualifies for adopted, I guess.
nicholst55
Brass Whore
Olympic Arms tried that with their proprietary .300 OSSM(?) cartridge. Back when they were still in business. It made a splash (big? small?) at SHOT in 2010, but I doubt if they sold more than a dozen of them.
http://www.gunsholstersandgear.com/2010/01/20/olympic-arms-gamestalker-chambered-in-300-ossm/
I shoot a 243 Win with 105 Berger Hybrids at just under 3000fps using H4350.... primers are slightly flat. The 6GT is cartridge most likely to produce similar performance with a +100gr 6mm bullet. Due to better case design developed from PPC/BR, the 6GT mirrors the 243 Win/6mm Creedmoor performance (velocity and accuracy) while using 1/3 less powder.
The 6ARC has less powder and similar, but smaller, case geometry. It doesn't have powder capacity to achieve anywhere near 3000fps with 108gr bullets.
Hornady brass is a good start. If cartridge gains wide acceptance then likely that Lapua will start manufacturing the case in a year or 2... military contract is big plus for helping it gain acceptance. In the meantime Lapua offers 6.5 Grendel brass that can easily be necked done to 6mm and bump back the shoulder to form 6ARC.
The 6ARC has less powder and similar, but smaller, case geometry. It doesn't have powder capacity to achieve anywhere near 3000fps with 108gr bullets.
Hornady brass is a good start. If cartridge gains wide acceptance then likely that Lapua will start manufacturing the case in a year or 2... military contract is big plus for helping it gain acceptance. In the meantime Lapua offers 6.5 Grendel brass that can easily be necked done to 6mm and bump back the shoulder to form 6ARC.
Yes, Olympic was very much on the leading edge of pushing the envelope of the "Standard" AR15. I do believe SunDevil also had a design in place similar to Olympics $$ 22-250 lowers. However Olympics downfall after Two Decades of dominance does not indicate Product Failure. All it takes is one company to set a Standard "Oversized" AR15 style modification and the rest is in the history books just like any other product. How obtuse to scorn innovation.
It will be interesting to see the M4 performance of this cartridge. 45 years ago things that I and others worked with slowly became SAAMI for civilian manufacture but this was announced as military and civilian immediately, I'm assuming based on the work by Barrett that this will be a specialist weapon up front. The 7.62 x 51 NATO has seen its day and the 5.56 x 45 NATO has now been pushed to the point of short rifle life with 62,500 PSI with the new X855A1. The 6MM ARC at 52,000 PSI certainly has a better chance of single projectile weight acceptance in both M4 and M16 configuration then the 6.5.
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The A2 I was issued in Boot was decent, the A2 I had in the Pacific was perfect & gave me multiple experts, the A2 I was issued to combat? pure worthless wore out falling apart garbage. I would have preferred the 7.62 anything when it came time to deploy. I'd prefer a weapon designed for 62k psi over a light duty handicapped long range paper puncher. Neither would be my 1st choice and it's really two separate applications that are being discussed not one. The AR15 was never designed for this sized Case head: .378" vs .440" it'll never be a winner in it's current configuration. It would require a platform in between the 10 & M4. I'd applaud the ARC for what it is, a commercially available 6mm PPC. Thank You Hornady.
I carried the M2 Carbine in the M1A configuration as my secondary for 3 inserts and then a Car 15. I've carried the M16 and M14 as well.
All my own opinion!
As the range closes the 7.62 x 51 is detrimental to accurate follow up, as the range exceeds 500 yards it shows that it's long in the tooth. The heavy 6 mm and 6.5 mm projectiles while not a modern concept their respective efficiencies in there current configurations are modern.
With a 5 1/2 lb rifle 110 grain projectiles slows accurate follow up so while I love the M1 and M2 30 Carbine for close work (200 yards-) it's best when modernized with a new stock to weigh about 8 lbs.
The Car 15 of my day evolved into the M4 and for close up and personal work to 300 yards it's efficient, at 400+ yards it's dicey and as the wind kicks up it's a more of keep their head down proposition at that range.
At 52,000 PSI the 6MM ARC is the same pressure as the original 5.56 x 45, which gives me hope for durability. It remains to be seen if 1 base cartridge with a108 grain projectile can work in an M4 at 14 1/2", the M16 at 20" and a specialty rifle with a 20" or a 24" tube. The logistics people love that.
Ballistics are great for the 20" & 24" barrels I question the performance in 14 1/2" barrels and the sustained fire tests need to be perfect. Since a man's ass is on the line I'd like to see an M4 and M16 in 6MM ARC run uncleaned for 5,000 rounds and see what gives.
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