The new Remington 6.8 mm?

[Big Paulie]

Ok Guys,

  Who has the scoop?  Remington is supposed to be releasing a brand new military cartridge, based on the old rimless .30 Remington, for use in full auto military weapons,  including the Army's M-16s.  Apparently, all that has to be done is for the upper and barrel to be switched by the Army on existing M-16s to be able to use the new round.   It is supposed to be a big improvement over the current 5.56 mm (.223) and the Army is on board with it?

  I guess that after two desert wars, and trying to shoot thorough clay buildings in desert towns, the Army finally figured out how lousey the 5.56 mm really is.  Apparently, 6 years in Viet Nam wasn't enough.

   I have just seen small snippets on this, and haven't seen any definitive articles.  Anybody got any info on this?

Thanks, Big Paulie

[Mikey]

Big Paulie:  Nope, like you all I have seen is snipets and no real information.  

Silly me, I would have thought that in order to keep as much of the current small arms inventory as possible and keep new equipment costs to a minimum, the military may have called for a simple bore expansion on the current 45mm length cartridge, so that current magazines, bolts, etc could still be used.  That would have given the troops a 6.5x45mm, which is just shy of the 260 but, silly me, huh.  

As I recall, the 30 remington was a bottleneck (yes???), meaning that the cartridge base will be larger than with the 5.56, and that will mean fewer rounds in the magazine.  The 6.8 means what, just another designation for the .264-.265 (or 6.5mm) bore???  Please don't tell me they went and developed a whole other bore diameter for the mickey-matic.  Geez, one might think that if they went to all that trouble, why the hay didn't they just go with the 260?????  Ah well.  Mikey.

[PA-Joe]

They should just go with the 7.62x39. Lots of ammo out there and guns. And it's what's beating us now.

[Big Paulie]

The only other thing I heard was that the new cartridge would give performance in the .300 Savage class.  Better than the .223, and milder than the .308.

[RaySendero]

....
As I recall, the 30 remington was a bottleneck (yes???), meaning that the cartridge base will be larger than with the 5.56, and that will mean fewer rounds in the magazine.  The 6.8 means what, just another designation for the .264-.265 (or 6.5mm) bore???  Please don't tell me they went and developed a whole other bore diameter for the mickey-matic. ....
Ah well.  Mikey.

Mikey,

The 6.8 Rem isn't a .264 (6.5mm) bore and its not new - Its a .270!!!

[Mikey]

RaySendero:  gasp, choke, gurgle, choke some more and gasp my last - dang Brother, didja say it were a 270??  Ya'll sure did, dinya - yep.  Oh my achin' Goodness.  

Now, that's gotta be a bit of a different looking round - based on the 30 Rem, shortened to 45mm (I suppose) and necked to .270.  Hmmmmmm.  Mikey.

[huntsman]

The .277 bore is actually 7.0358 mm, so I don't know where the 6.8 mm measurement figures into this. The 6.8 mm bore measurement converted from metric to inches would yield .268 in., which has no current standard factory equivalent, but the closest thing would be the .264" = 6.71 mm (6.5 mm).

Either the .264 or .277 would yield better performance results on targets with a FMJ bullet than the .224. Based on the .264 bore and a bottlenecked case of the same general dimensions as the .223, then we are looking at a weaker ballistic cousin to the 6.5 mm Japanese Arisaka. The Arisaka is capable of delivering a 100 grain bullet at @ 2650+ fps, a 120 grain bullet at 2500+ fps, or a 140 grain bullet at 2400 fps. The smaller cousin wouldn't be quite capable of that, but still could probably push the 100 grain at around 2300 - 2400 or so, and the 120 at close to 2200. That's a significant improvement in effectiveness over the .223 by any measure. The loss in trajectory wouldn't be very significant compared to the gain in stopping power.

[RaySendero]

RaySendero:  gasp, choke, gurgle, choke some more and gasp my last - dang Brother, didja say it were a 270??  Ya'll sure did, dinya - yep.  Oh my achin' Goodness.  

Now, that's gotta be a bit of a different looking round - based on the 30 Rem, shortened to 45mm (I suppose) and necked to .270.  Hmmmmmm.  Mikey.

Mikey,

I saw a set of pictures of all the test rounds using that 30 Rem casing.  The cut down 30 rem case is said to fit 28 rounds into a 30 round .223 clip!  There was a 6mm, .257, 6.5mm, 270, 7mm, 30 caliber.  Yes, a true .277  270 - Where they got the 6.8 name I haven't a clue!?

The 6.5, 270 and 7mm were said to perform the best.  But of the three the 6.8 was picked as the "better".  I don't recall all the criteria miliary used to evaluate the caliper.  Close range stopping-power, long range energy, and trajectory were all figured in somewhere along with the fact that the M-16 could be fitted to fire the new round.  What I'm reading lately though is the military ISN'T goin to adopt the round - GO FIGURE!  I believe any one of the three "best performers" would be better than what they have now (223).

[Slug-Gunner]

The .277 bore is actually 7.0358 mm, so I don't know where the 6.8 mm measurement figures into this. The 6.8 mm bore measurement converted from metric to inches would yield .268 in., which has no current standard factory equivalent, but the closest thing would be the .264" = 6.71 mm (6.5 mm).

Actually, if you convert .270 caliber to metric it comes out to 6.8580 mm, so it's pretty close. Reversing the conversion from 6.8 mm to inches = .267716 inches or caliber. Maybe it was calculated by a recent college graduate.... most of them "suck" at math skills, especially "metric" conversion.

[huntsman]

S-G,

The .270 caliber is actually a bore diameter of .277 inches, thus the conversion is actually 7.0358 mm. Another one of our many "bore diameter vs. caliber name" anomalies that are just plain senseless. This is what happens when there is no standard used to name things. Perhaps this fact was also overlooked by whomever came up with the "6.8 mm" moniker.

Regardless, it would be very interesting to see some work done on a shorter-cased version of the .277 bore diameter. Based on the performance of the .270 Win cartridge, I'm amazed that some manufacturer hasn't already tried this. It would fill a lot bigger niche in the gun world than the short-super-magnums that are all the rage of the manufacturers right now.

The .223 Rem can push an 80-grain bullet at @ 2800 fps, so it seems reasonable that the same cartridge could be necked up to .277 and deliver, say, a 120-grain bullet at somewhere near 2200 fps. Not a whopper round, but still better in penetration, wound channel, and overall performance than the .223. It strikes me that this cartridge would be slightly smaller in case capacity to the 7.62x39, but deliver a bullet with a better sectional density at slightly less velocity. Expand the case diameter a bit and you could about match the velocity and have a lot flatter-shooting and better-penetrating round than the 7.62x39. Not a bad formula, at least in theory.

It would scare the urine out of me to think I had to shoot at someone in the opposite trench with only a .223 Rem. I would much rather have something that would more likely KILL a 200-lb human with one shot. I would trade a .223 Rem with 80-gr rounds for a "7.04x45" with 120 gr rounds any day of the week. Wonder what the boys in the trench would choose....

[RaySendero]

....
The .223 Rem can push an 80-grain bullet at @ 2800 fps, so it seems reasonable that the same cartridge could be necked up to .277 and deliver, say, a 120-grain bullet at somewhere near 2200 fps. ....
....

huntsman,

I've read where the 6.8 Rem SPC has a nominal bullet weight of 115 grains and velocity of 2,650 from a 16.5” barrel - Better than you would think!  Remington lists the velocity for 115 grain bullet as 2,800 from a 24" test barrel on its web site.

[Rummer]

Guys,

I think I figured the metric conversion.  a .270 has a .277" groove diameter and a .270" bore diameter.  .270 x 25.4= 6.858mm.

I wonder why they went with .270 instead of 6.5mm?

John

[huntsman]

My guess on the 6.8 instead of 6.5 would be that the 6.8 is a better compromise between a good sectional density (smaller diameter is better) and shorter OAL for a given bullet weight (larger diameter is better). The shorter AOL is likely to have less feeding problems from the existing shorter magazines. I would think in the field better feeding characteristics would be more important than a slight edge in SD. Just my opinion, of course.

[magnum308]

Hi. I'm from Australia and I've just joined this website. We're a bit behind things over here but you might like to check out the March/April issue of Rifle Shooter magazine it has an article on the 6.8mm Remington SPC. So it's no longer rumor.

Magnum308[/i]

[longwinters]

Welcome Magnum308.     Nice to meet you.

long

[Rscout6945]

just read yesterday that T/C is looking at adding the 6.8 in the factory lineup for the G2 Contender soon.  Should be great for rifle version

[MGMorden]

I've been very interested in this cartridge myself.  I still think that it would have been better to just neck up the .223 case to accept 6.5mm bullets, but if the army wants to spend more money retrofitting then that's fine.

What I do find truly "neat" about this round though, is that unlike the .223/5.56, this is actually starting to get into big-game huntable power levels.  Military cartridges sore in popularity level (always have) and plumment in price b/c of this, so it would be nice to actually have a nice hunting rifle that would actually be CHEAP to practice with .

[Leftoverdj]

115 grain bullet at 2650 fps pretty much duplicates the .250 Savage and no one ever complained about it as a game killer. Shouldn't be any trick to building a rifle on one of the baby Mauser actions that would weigh in at under six pounds, scope, sling, full magazine and all.