U.S. Military's 'New' 6.8 Caliber Round ?

I still dont understand what gun this new bullet is going in?

Even IF we do need a better caliber because artillary and CAS are no longer available (really a rare occurance, but whatever), what platform is this meant for? If its going inside a LMG, Im all for it. Longer plunging fire and better terminal affect when it does get there, sure. If anyone thinks this belongs in a carbine, and will all of a sudden make every trooper into a DM and assaulter at the same time, no F'ing way. There is a reason we dropped 7.62 and adopted 556 as the main battle cartridge. When I was in Afghanistan it was all about the caliber over match and CAS. If dudes shot at us with AK, we returned with 240 & 50 cal. If they where using anything bigger than AK, again returned with 240 & 50 cal and then CAS got invovlded. The absolute name of the game was fix target with belt feds and wait for CAS or artillary. Really too simple.

id say we adopt something like the 6.5 Grendel if anything and 6.5 creed for lmg's and dmr's. A intermediate with a high BC and rounds with high BC in general would be very adaptable and useful cartridges. The 6.5 Grendel can stat super sonic for 1000 meters and retains lots of energy. That's the route I would go but im just some geek on the internet. A 6.5 g with slightly higher muzzle velocity would be the ticket. I agree with the general consensus that this 6.8 will probably be of limited use if not shelved.

Quote:

---

Originally Posted by ssimo

The idea of a major conflict between modern countries without the air superiority being the crucial point is not realistic. In order not to have artillery you should go back to medieval technology, there wouldn't be rifles, too. you are basically talking about a post apocaliptic world war, which i don't Think was the topic being discussed here. The caliber for the single Soldier or the single infantry unit can make a big difference (and I still think That is better to have more round and Carry less weight) but, unless we are talking about A completely different kind of Bullet with a New Technology Behind it, I don't see many caliber options to really improve a Western country armed force performances at the moment.

---

In a near peer conflict artillery will be spending the majority of it's time doing counter battery fire or moving to avoid enemy fires not providing close support.

Quote:

---

Originally Posted by jpmuscle

Maybe they should carry PCCs?




On a serious note new calibers and their derivatives are cool and all but how much further can 5.56 be evolved? Or have we already exceeded the apex of its potential?


Sent from my iPhone using Tapatalk

---

Haha. Pistol bullets actually weigh more.

Don't forget that smaller diameter bullets have less fluid drag when impacting the target as well. It works both ways. Longer, thinner projectiles produce less drag in air, a low density fluid (technically air is a gas, but in terms of movement of air around a projectile, it follows the same patterns as fluids). They also produce less drag in the target's body so they actually need to retain greater velocity to get the same expansion / fragmentation! If there's less area in contact with the medium, a higher velocity is required to achieve the same force per a square inch against the projectile itself from drag even though the force per a square inch of the projectile is higher against the medium it is penetrating. So when it comes to damaging the medium, you want the projectile to spread that force around more to discharge as much of it's energy as possible. When it comes to getting the projectile to expand or fragment, you need to generate a high force per a square inch to cause deformation of the projectile itself so it can discharge as much of it's energy as possible into the target.

All of these projectiles are made of the same materials and require a certain amount of force per a square inch to cause either fragmentation or expansion upon impact. While longer and thinner projectiles may preserve moment better at longer ranges due to less drag in the air, they also have more difficulty effectively delivering that energy into the target, so they actually need that extra energy to have the same effect as a lower velocity, but larger diameter projectile.

When you have a finite amount of energy at the muzzle, there's a happy medium where you balance everything. A magic projectile, if one existed, would be very thin and long during flight through air (to preserve energy) then suddenly grow to a large diameter at the moment of impact or just before to cause the greatest fluid drag and hence energy delivery into the target. Since none exist, the most practical and broadly effective will be a balance of the two, which 6.8 diameter projectiles in the 110gr to 115gr weight tend to do based on the testing I've seen. More muzzle energy also means greater recoil, so again even if you could some how get 7.62x51 energy from a 6.5 Grendel or 6.8 SPCII sized cartridge, you'd still have the major issue of substantially increased recoil which negatively affects the speed at which another shot can be taken accurately enough to have positive terminal effect on the target. The middle ground was a balance of that aspect as well as balancing terminal performance at both close and intermediate ranges.

And just like 5.56 77gr loads, you can make 6.8mm heavy loads as well. So comparing the best long range 5.56 variants to run of the mill 6.8 is stupid, because you can tailor the load for any caliber for better close or longer range performance. Sure, the military isn't likely going to adopt the actual 6.8 SPCII cartridge, however the original 6.8 SPC development by the miliary proved the concept the Russians figured out back in the late 1940's (7.62x39) and it is a modern rendition of that concept. For civilian use, 6.8 SPCII is the do it all cartridge for the AR15 frame size. Ask anyone that hunts hogs, deer or other medium game in the 150lbs to 200lbs+ range, the larger calibers (than 5.56 / 5.45) are preferred for their superior terminal performance even though the smaller calibers can perform adequately with the right loads in most situations. Shot placement always matters, but it matters a little less with better terminal performance and the heavier projectiles have far superior barrier blind performance over the small caliber loads which matters when hunting hogs / deer in dense brush or in fighting applications through common barriers.

Here are some of the references I used when I made the decision to switch from 5.45x39mm (originally started off with an AK-74M) to 6.8 SPCII (I seriously considered 5.56 for it's broad range of choices or 7.62x39 and 6.5 Grendel for it's superior wounding over 5.56). But when it came down to it, the 6.8 provided that just right balance without some of issues associated with the older non-native adaptations (like 7.62x39 AR's have) or the limitations of the smaller calibers.

https://ndiastorage.blob.core.usgovc...tl/Roberts.pdf

http://www.frfrogspad.com/68spc.htm

http://demigodllc.com/articles/6.8-m...-arms-carbine/

https://www.ar15performance.com/6_8_barrels

https://www.ar15performance.com/faqs (some great info at the bottom related to 6.5 Grendel and why it's development seemed to stop)

It will be really interesting to see what they settle on.

Good Morning Kids, What I personally would love to see, are some USGI AAR's pertaining to the actual, 'real world ' performance of the 6.8 SPC Cartridge from the select U.S. Special Operations units that have fielded them in the combat arena.

We all know that they're out there, however getting hold of such data may be quite difficult. I too am an proponent of laboratory tests, charts, etc., but I won't be satisfied until I've had access to actual, field reports from the units using these 6.8's in theater combat operations. OK, Boys, let's send out all the minions & attempt to dig up a few such reports.

Personally, I absolutely love my 6.8 SPC [Spec. II], & was an early proponent of the caliber. Mine's nothing special, just a Stag Model 5, very early production, just after their switch to the Spec. II chamber. I say that this Star's fit & finish is literally on par with any of my older Colt's, or even my LMT / 308-MWS. IN was seriously impressed upon receiving it, & it's trigger matched the finish, superb ! IIRC, my example is in the 28XXX Serial # range, & it really appears as if Stag put a lot of emphasis on producing a quality product, at least at that particular time.

Now however, my Stag 6.8 SPC just sits in the safe, ready if I ever do require it's services. A few years ago I happened a load of the Normandy 'TAP' ammunition, all with 110 grain heads. I picked up 200 rds of standard TAP, along with 200 ers of the 'Urban TAP' variety. Those batches, along with a small lot of Remington 110 or 115, [ Can't recall which at the moment. ] should handle anything that arises.

I truly hope that our U.S. Military & Government Forces seriously 're'-consider the apparently overlooked 6.8 SPC Cartridge as an combat arms option. But, as always, in the end, it's usually the 'cost counters' that will either nix, or push forward the adoption of anything for our Military / Government useage, or purchase. So, as usual, we just have to wait & see what, if anything the future will bring us ?

Best, dpast32

6.8 SPC is not part of the current discussion and does not come close to meeting the requirements the military set forth.

Quote:

---

Originally Posted by Arik

I'm all for it even if it's ultimately doesn't go anywhere.

Innovation is always good. This may not go anywhere but it may lead to something else. Not long ago 300BLK was a wildcat cartridge. 222 spawned 223 and why do we need 223 when 308 already did everything..... which came from 3006 ...from 3003...etc..

Everything we have today was at one point in time pointless because we already had other stuff. People using the atlatl were probably looking at the guy building the first bow as a waste of time and energy

Like concept cars. They may never be built for sale but their tech eventually bleeds into cars that are.

---

Innovation is almost always a good thing. However, with the military, many times the innovations aren't utilized because the military wanted pie-in-the-sky and the innovation was only a step or two ahead. I believe it all goes back to the money. If it didn't, then the man on the ground would be the top consideration rather than the latest billion dollar toy.

Quote:

---

Originally Posted by Tuukka

And most importantly, more good training and range time.

---

Yep! yep yep yep. More ammo and more training and range time. More quality training that is.


I could see them scrapping the whole thing and going with that effing 6.5 creedmore. At which point I'll go AWOL...