Somebody educate me on the 6.8SPC round please

[Kenny]

I am looking at doing a trade for one all RRA with a YHM FF handguard. I know nothing about this round is it comparable to the 6.5 Grendel? Is the ammo hard to get? Is it something I will never be able to sell? Which is better 6.8SPC or 6.5 Grendel?

[bhannah]

I am looking at doing a trade for one all RRA with a YHM FF handguard. I know nothing about this round is it comparable to the 6.5 Grendel? Is the ammo hard to get? Is it something I will never be able to sell? Which is better 6.8SPC or 6.5 Grendel?

I was interested in the 6.8 when it came out but there were some issues with some of them.

the original SAMMI specs of a 1-10 twist and 6 grooves is not optimal and not a viable set up for the cartridge. These are not the specs originally provided by Holland and co and are actually an abomination caused by remington. Some places even sell a 1-9.5 twist barrel wich is asking for trouble... these specs lead to many problems and poor performance mostly becuase of overpressure... this is similar to the .223 / 5.56 chamber issue...

 

The minimum acceptable specs are the SAMMI SPEC II chamber and a 1-11 twist with 6 grooves which many companies that were in the dark or just stubborn are changing to... Ideal would be a 1-12twist 3 groove and some have even tested 1-13 twist barrels for this cartridge... 6.8 Ammo manufacturers have had to download thier cartridges becuase of this and instead of getting close to 3000 fps they were getting 2500 or less...

 

I would just verify that the twist is correct.

But from what I have heard the grendal has better ballistics.

But the 6.8 is gaining in popularity.

[CraigC]

The 6.8 is becoming more popular and there are factory loadings for it. The 6.5 is a better long range load with high boc bullets, but it is better suited to handloaders because Alexander Arms has not standardized the round. Nobody but Alexander will chamber the 6.5, but several large shops and a few high end barrel smiths such as John Hollenger at White Oak are chambering the 6.8 . The 6.8spc has a SAAMI spec and there are is a wide bullet selection on the market because it uses the same projectile as the 270win.

 

What are the other specs on the rifle (i.e. barrel length, stock, trigger, gas block, muzzle device)? The only thing that I would change that you mentioned is the YHM handguard. Is it railed or a tube? In my experience their railed forends tend to be well made, but very heavy and throw off the balance of the rifle. Find out if it has RRA's two stage trigger. For the money they are the best non-adjustable AR triggers on the market (except for premiums such as GA's SSA).

 

Let me know more about the rifle and I can give you a more detailed answer. Building high end AR-15s is has hobby of mine since I got out of the Army a few years ago. A lot of shooters would consider me a gear snob, but I can give you the straight poop on the rifle.

[mauserme]

I'm no expert on this but I do have a Bison Armory 18" SPR upper on order and have done a little research. You could actually learn alot more than I know by visiting the 68forums

 

The round was developed by Remington at the request of some special forces guys who wanted to improve on 5.56. Maximum bullet weights are around 115 grain but Speer (?) has some 130 grain that will still fit in an AR mag well. Silver State Armory makes good commercial ammo with S&B and Hornady also selling this caliber. If you handload you can get 3000+ fps with 85 grain bullets. I don't hunt so this is not from personal experience, but the round seems to be very good for deer and hogs out to 200 yards or so. I've seen claims for cow elk at 275, but that seems like a stretch.

 

 

Remington messed up the original specs and the early chambers are known as 6.8 SPC. These came with barrels with 9" or 10" twists and you do not want these. High chamber pressures limit velocity too much. The currently accepted chambers are 6.8SPCII, DMR-C, or with AR Perfomrance some are marked 6.8x43. Basically, these newer chambers have a little longer leade. Barrel twist should be 1:11 or 1:12 3 groove, 4 groove, or 5R. The consensus is also that M4 feeds ramps are a necessity since the round is a little fatter that 5.56 so the tip of the bullet sits a little lower in the magazine, but Stag makes a 6.8 without the M4 ramps and it has a good reputation.

 

When i was looking for an alternate caliber upper I chose 6.8 first over 6.5 Grendel for a few reason ( and I stress first - I can see getting a 6.5 down the road and don't really get into the argument about which is better. They're both good for their intended purpose).

 

> The fact that specials forces asked for this round speaks to my sense of utility

 

> 6.8SPC is open for any manufacturer to make; 6.5 is proprietary with Alexader Arms controlling production. Only AA can use this designation on their chamber and only they and Wolf (under license) make ammunition so designated. Others are using different names to get around this, but this adds confusion. Les Baer is supposed to be making a .264LBC chamber and round soon that will also chamber 6.5 Grendel. This might help the 6.5 along.

 

> 6.8 balistics are similar to the .276 Pedersen (comparing the lighter bullets) John Granand originally wanted for the M1. I hardly ever jump on new guns/new rounds but this speaks to my sense of history

 

> 98% of the potential for 6.8 is acheved in a 16" barrel and it is still efficient in the shorter barrels favored by the military. The Grendel really needs more barrel to see its potential - maybe 22" or so. I think the military, if they adopt either round, will prefer the 6.8 for this reason.

 

> Most major, and several small, gun makers are chambering 6.8 now though some of the bigger names have been slow to change to the newer specs.

 

 

On the plus side for 6.5 Grendel

 

> The ballistic coeffecient for these bullets is far superior to 6.8 so long range shooting is where this round shines. This is a 1,000 yard round in the right gun.

 

> Ammo, though not as easily found as 6.8, is cheaper when you can find it. Roughly $14 per 20 for 6.5 versus $20 on up for 6.8. Keep in mind, though, that no one currently makes FMJ in 6.8 but Silver State Armory promises some $14 plinking ammo later this year.

 

 

 

Will you be able to sell the 6.8? I think RRA is still using 10 twist barrels so this might limit your options.

[bemidji]

Kenny - here are a couple links that may help (or not).

 

The first post in this thread has some info but the thread quickly deteriorates in a pissing contest after that.

 

Fr. Frog hasn't updated his page in a while but still has quite a bit of info.

 

Everything at those two links back up what everyone else has posted.

Went to the RRA website and every barrel I saw listed for their 6.8 offerings were still 1:10 twist.

[Kenny]

So should that be a deal breaker? I have a guy that wants to trade me a Remington 700 in .308 with a bipod & custom stock all bedded and the Rock River 6.8SPC it does not have the 2 stage but I have some nice triggers laying around. I have to give up my AR-10 but I get to keep my scope & Larue mount. I think this sounds like a pretty decent deal for me figuring I can sell at the very least the RRA for $850-$900 and the 700 for around the same. He is also throwing in 60 rnds of 6.8 ammo.

[mauserme]

So should that be a deal breaker?

 

I don't know. Maybe I'm too particular about twist rates. Silver State specifies minimum SPCII 1:10 6 groove to use their combat loads which are pretty hot, so you might be OK. Like bhannah said its sort of like .223 v 5.56 except some people argue .223 chambers are more accurate than 5.56 becaase they're tighter. Nobody makes the same argument about tight 6.8 chambers - they're just over pressure if loading to full velocity. I think the worst you would see with a faster barrel though is slightly reduced velocity for any given chamber pressure.

 

 

For my $900 I really wanted the best specs I could find, but it depends on how much the Remington 700 is worth I suppose.

[Kenny]

So should that be a deal breaker?

 

I don't know. Maybe I'm too particular about twist rates. Silver State specifies minimum SPCII 1:10 6 groove to use their combat loads which are pretty hot, so you might be OK. Like bhannah said its sort of like .223 v 5.56 except some people argue .223 chambers are more accurate than 5.56 becaase they're tighter. Nobody makes the same argument about tight 6.8 chambers - they're just over pressure if loading to full velocity. I think the worst you would see with a faster barrel though is slightly reduced velocity for any given chamber pressure.

 

 

For my $900 I really wanted the best specs I could find, but it depends on how much the Remington 700 is worth I suppose.

 

 

I could always order another bbl & replace it if I felt the need. The 700 honestly is probably worth close to $900

[mauserme]

If the AR and the Remington were keepers I think the trade makes sense.

 

If they're for resale look at the numbers:

 

AR10 Dealer Price (guessing): $1300

AR Trigger: 125

Labor for Trigger: free

6.8 Barrel: 200

Labor for Barrel: free

Total: $1,625

 

If the AR and Remington can be sold for $850 and $900 you stand to make $125 if my numbers are correct, or alot more if you don't need to upgrade the AR15.

 

BTW, my Bison upper just walked in the door. Its a thing of beauty. For what its worth this build will end up costing a few hundred more than you're asking for the RRA, depending on the trigger I use. So a 6.8 in the $850 to $900 range just might move quickly.

[CraigC]

So should that be a deal breaker?

 

I don't know. Maybe I'm too particular about twist rates. Silver State specifies minimum SPCII 1:10 6 groove to use their combat loads which are pretty hot, so you might be OK. Like bhannah said its sort of like .223 v 5.56 except some people argue .223 chambers are more accurate than 5.56 becaase they're tighter. Nobody makes the same argument about tight 6.8 chambers - they're just over pressure if loading to full velocity. I think the worst you would see with a faster barrel though is slightly reduced velocity for any given chamber pressure.

 

 

For my $900 I really wanted the best specs I could find, but it depends on how much the Remington 700 is worth I suppose.

 

 

I could always order another bbl & replace it if I felt the need. The 700 honestly is probably worth close to $900

 

If you want to replace the barrel give John at White Oak a call at 309-376-2288. Having his barrel is a selling point when you list it. The only draw back is that he often has very long lead times for orders. The last barrel that I bought from him took 4 months, but I think he's pretty much caught up so its probably quicker now.

 

I'm not sure if he's cutting 6.8 or not, but I'd also call Frank White at Compass Lake Engineering. My last barrel from him was done in less than a month. His number is 850-579-1208.

[templar223]

I am looking at doing a trade for one all RRA with a YHM FF handguard. I know nothing about this round is it comparable to the 6.5 Grendel? Is the ammo hard to get? Is it something I will never be able to sell? Which is better 6.8SPC or 6.5 Grendel?

 

I'm hearing and reading more and more that it's on its last legs.

 

Probably be as common as a 10mm in a few years and as common as 32 gauge in twenty.

 

John

[mauserme]

I almost forgot if you do re-barrel the AR15 you'll need a 6.8SPC bolt and maybe throw in a magazine (yeah, the magazines are different too). The proft margin just got a little tighter...

[Kenny]

I almost forgot if you do re-barrel the AR15 you'll need a 6.8SPC bolt and maybe throw in a magazine (yeah, the magazines are different too). The proft margin just got a little tighter...

 

The gun is already a 6.8 so I would just need a bbl only.

[mauserme]

The gun is already a 6.8 so I would just need a bbl only.

You did say that right up front, didn't you.

 

Duh ...