I’m currently doing my D.D. on the 6.8 SPC Cartridge, do any of you have experience shooting, or testing the cartridge?
What would you consider it’s maximum range, and how are the groups at that range?
Lastly…what length barrels did you shoot it with, and velocities recorded?
That about sum’s it up, and thank you for the information in advance.
I can barely afford to shoot the amount of 5.56MM I like… for me switching to 6.8MM just ain’t happening… would make it even more expensive.
Just my take
The main reason I decided to go with a 6.8 is because of its size, and even that is two fold.
1: Its bigger than a 223/556
2: It still fits in a 223 sized AR-15
The 6.8 is just a neat caliber. It gives me the same traj as a 77gr 223 and a 308 168gr SMK. So its range is just as good as a 38, to an extent.
So the 6.8 will have pretty much the same range as a 223, it will just hit harder. Though if you handload a SMK fairly hot, I think you might get a better traj than a 223.
My gun was built by Grant.
16.1 Noveske brl
Troy 12.0
With Rem OTM ammo I am getting right at 1.25MOA @ 100 yards with it. Handloads will get better than that. The recoil is subjective. My gun has a vortex fh, but I am going to swap it out for a MSTN brake. The recoil isnt bad, not much more than the 223, I just want to stop the muzzle rise.
http://coloradomultigun.com/misc/sgn_68spc.pdf
that link will tell you pretty much everything you want to know.
Thanks for the info so far, I will read the link when I get more time.
More retained energy downrange in the same sized weapon as 5.56mm. It’s that simple. I give up three rounds in the mag and a negligable increase in recoil. At the rate 5.56mm ammo is increasing in price, it’s not that much more expensive to shoot 6.8mm SPC (apples to apples; you’re not going to find surplus 6.8mm).
Stephen
A better BC (than 5.56) out of a short bbl. That’s my reason (10.3" bbl).
Sean
With ammo prices going through the roof I don’t see myself leaving 5.56mm any time soon.
If anything my next move will be to .308.
I’m seriously thinking of getting OUT of 7.62mm because it is a service round and 6.8 SPC might fall through the cracks on the next bout of gun-grabbing (if ammo taxation is part of it; Moynihan once proposed taxing .45 ACP, 9mm, 5.56mm, 7.62mmX39, and 7.62mmX51.) The price differential between good 5.56mm (Black Hills) and 6.8 SPC is narrowing. The 6.8 SPC requires less powder per round than 7.62mm and bullets are SMK’s are about 75% of 7.62mm varieties when reloading costs are considered. Plus, M1A’s (my 7.62mm of choice) have a whole different manual of arms.
Knowing what I know today (what has been posted above), if I were just starting out, I would probably go with 6.8 SPC and a dedicated .22LR upper for practice.
Very thought provoking. The one thing that’s kept me away from the 6.8 is the cost, however, in light of the narrowing of the gap and the fact that the “antis” will not be so generous the next go around (read more thorough), the build I’ve been planning may just take a new direction. Don’t think I’ll give up on the 5.56 though.
Two words:
Bolt breakage.
Anyone got data on the parts failure of 6.8s run hard?
Very interesting comments from everyone (thank you), I would really like to hear more about failures, and any bolt breaking issues.
Those two words are why I haven’t (yet) put money into 6.8SPC. No matter how good the cartridge, it is no good if you can’t keep the gun running over time.
Yes, from more than a couple reliable sources, but anytime I bring them up the “experts” quickly tell me I’m full of shit, and the issues were faulty parts and not the cartridges fault. But - those issues were with the cartridges loaded to the specs of what they were supposed to be, not the lower pressure round they ended up as.
The ONLY reason to buy a 6.8 is bacause you want one. If you sleep better at night because you convinced yourself you have a more deadly carbine, good for you, enjoy your hobby.
The only bolt breakage data I had was from the earlier spec’d ammo
Anyone ask Zak what life he is getting? However I hardly view replacing a bolt at a rate that is about twice the 5.56mm to be a deal breaker.
Doesn’t that sorta’ depends on if we are talkin’ DPMS- or Colt-made bolts?
Would it not depend also on the price and availability of said bolt?
At what round count do you replace a 5.56mm bolt?
This reminds me of the “Perfection” of 9mm Glocks:rolleyes: being lost when the design was scaled up into larger calibers.
An Active Duty SF Sergeant used to publish a quarterly entitled, The Resister. He once included a political cartoon of a carbine in a case with a glass front with a hammer attached to the frame. Under it were the words “BREAK GLASS IN CASE OF TYRANNY”. Oh, it is a hobby; nevertheless, it is much, much more.
I’m sure a lot of folks lose sleep over just that. Not me. When it comes to that, the willingness of the individual will be what matters. The caliber of the weapon is insignificant, be it a .22 revolver or a U-Haul full of fertilizer and diesel fuel.
You need to do/buy/train as you see fit. When the times comes you’ll be responsible for your decisions.
And for those of you who already have a 6.8, what kind of accuracy did you get, and at what ranges??
With commercial ammo ( Remington, Hornady, SSA Xtreme ) you can expect to get 1.25 MOA @ 100 with an good AR. With a bolt gun it will be better.
With handlaods, and SSA matchkings You can probably get pretty close to 1 MOA @ 100. At least thats what its been for me so far.
My 6.8 has a 16.1 noveske, and a 6x scope, and I know the trigger puller isnt the best. I would assume that if you had a 20 or 24" brl it might be more accurate.
Do grendel guns have the around the same ammount of bolt failures also?
Well… that means we’d be getting 1500-4000 rounds out of a 6.8 bolt, 1500 in a hard-run gun. I’m all for PMCS, but a gun that may have a bolt failure after 1500 rounds is unsat, in my book. Especially when I can get 80% of the 6.8’s performance out of MK262 in a properly set up gun.
piss poor cost:benefit ration for me but Ymmv.