6.8 Info needed please

[darko]

I am considering getting a 6.8 upper for my Ruger SR-556 and could use some help. First, who makes reasonably priced uppers that would be compatible with my Ruger lower?

Second, I've heard that there are some type of spec II 6.8 ammo requirements and certain barrel twists that are needed. Could someone shed some light on these things for me and which companies make uppers that meet these requirments (remembering that it must fit my lower)?

 

[thesheepdog]

Could someone shed some light on these things for me and which companies make uppers that meet these requirments (remembering that it must fit my lower)?

Any 6.8/6.5 upper will fit any 5.56 lower.

 

[DnPRK]

http://www.bisonarmory.com/

 

[Polinese]

Doesn't the SR-556 come in 6.8?

 

[bedlamite]

Polinese: yes it does, but Ruger uses a SAAMI chamber an 1:10 6 groove rifling which is exactly the combination to avoid.

SSA is the Company that loads ammo for the better spec barrels, but to get it you have to order directly from them. All 6.8 ammo will chamber in all 6.8 guns, but the hotter SSA loads should not be fired from SAAMI chambers.

For barrel specs, You want either a SPC II, DMR, or 6.8x43 chamber. Essentially, anything except a SAAMI chamber is good to go.

Many companies still use the 1:10 6 groove barrels intended for 270 Winchester. They do this because it's cheaper, not better. The land/groove ratio is wrong and will increase pressure while decreasing velocity. The best barrels in 6.8 have a 1:11 to 1:13 twist, and 3, 4, or 5 grooves, and may have ratchet or polygonal rifling.

http://68forums.com
http://www.ar15performance.com/
http://bisonarmory.com/
http://global-tactical.com/
http://www.noveskerifleworks.com/

 

[tirod]

Check with the folks at 68forums to see what is the optimal set up.

Actually, very few companies offer the "wrong" specs. Most makers went to the longer leade and slower twist to maximize speed and accuracy, and allow shooting the few hot Tactical loads on the market.

ALL the rest of the ammo is loaded to SAMMI specs, and which barrel you use won't make it better. If you buy a Ruger or one of the few SAMMI chamber 1 in ten twist barrels, just don't shoot hot loads. The boxes are marked appropriately.

Want more speed, shoot 85gr Barnes, you'll get it. Want more hitting power, shoot bigger than 110's, you'll get it. Unless you like reloading and fiddling with the charges, overall length, etc., treat it like you would any other hunting caliber, match the weight to the game.

It would be nice if the spec wasn't limited by the SAMMI short leade, but the caliber already has double the power and nearly the same speeds as 5.56. Don't let that perspective get lost in the effort to improve things a few more percent. Get the better setup, sure, it's actually hard not to, but don't let some of the finesse points get out of hand.

For hunting, the 6.+ calibers are a huge improvement, let you use the AR action in the field, and for some states, make it legal. Don't expect taxpayer supported cheap military surplus, buy ammo like you would for any other hunting rifle, and enjoy it. I'm building one to do just that.

 

[Klingon00]

Seems to be a good price and I've heard good reviews on it but have no personal experience with it myself.

http://www.spikestactical.com/z/index.php?main_page=product_info&cPath=126_127&products_id=393

 

[darko]

Update-

Well, I ordered the Bushmaster 6.8 complete upper today from Buds. I phoned to verify the specs with Bushmaster as Buds was not able to answer. The upper is supposedly chambered for Spec II ammo with a 1/11 twist. Hopefully this is the case and I did well. If not, try not to pee in my cheerios overmuch.

Also, I ended up buying a Stag complete lower for it as I wanted to just have a complete rifle instead of swapping uppers back and forth on my SR. All told the complete rifle (upper and lower) has run me around $750 (not too bad-I think).

Hopefully, I did okay on my choices. From what I have seen so far ammo appears to be very limited and expensive. This will definately not be a plinker. Ammo and perhaps an accessory or two should finish this project out. Fingers crossed as this rifle is new territory for me.

 

[10-96]

Sounds like ya done good. I've got an AR or two that're both a ways down the quality chain from Bushmaster, I'm not exactly gentle with em, and neither one has blown up, regurgitated any parts, started speaking french, failed to fire or eject... in fact- they just keep doing what they were designed to do.

Depending on which ammo you get, you might end up getting a lighter buffer. That and a little break in time ought to be all you need. Save your paperwork and shipping receipt just in case there is a problem, but the odds are great that everything will be fine. Shoot, shoot a lot, and enjoy.

 

[giaquir]

I just recieved a Rock river Arms
coyote carbine in 6.8.
RRA guarantees 3/4 moa
and I love it.
They also make uppers.
Just a suggestion

 

[tirod]

From the perspective of most hunting ammo available - including internet sources - 6.8 is actually cheaper than some. A box of 20 from SSA can run $5 -8 cheaper than .30-30 Leverevolution from Academy. It's a matter of volume buying from the right source, just like anything else. Even the Marts can be beat out, and ammo can be shipped direct to your door.

Again, check the 68forums, you will find dozens of vendors available.

What's nice about a hunting rifle is that you DON'T shoot it in volumes. You can pick a caliber for it's ballistics. Look around, be honest, check the calibers, $1 is AVERAGE. The only cheap ammo is .22 or military surplus that was adopted over thirty years ago. That's a very short list: .30-06, 7.62 X 39, 51, 54R, .45, 9mm. Maybe some pre WWII stuff, .303, or metrics abandoned 50 years ago.

That's less than what, 2% of the calibers available? No, 6.8 is very available, in a wide variety of loads and sources. It's a matter of knowing where to look - and certainly not at the Boxmart. They sell Fudd fodder that's best avoided, not made the standard.

 

[tulsamal]

What's nice about a hunting rifle is that you DON'T shoot it in volumes. You can pick a caliber for it's ballistics. Look around, be honest, check the calibers, $1 is AVERAGE.

I guess somebody has to say this. Might as well be me. I agree that 6.8 is essentially "the same" price-wise as most centerfire hunting ammunition. The other way it is the same is that I can't understand people who can own and shoot such things without reloading for them! It just isn't that difficult to sit down and knock out 100 rounds of 6.8 for the same price you would have paid for 20 factory loads! Just like 7mm Magnum or any other hunting cartridge.

Gregg

 

[darko]

Yeah, a buddy of mine (and fellow gun-nut), was also urging me to start reloading, particularly for 6.8. I am not opposed to it and came pretty close to going the reloading route a few years back when I bought a 45 colt (also expensive ammo), but my problem is space. I just don't have an acceptable/usable area in my house to set up a bench.

I did find some Remington 6.8 115 grain ammo on sale at Midway for $15 something a box and bought a few. I'll probably pick up a box or two of the expensive hunting loads and use them sparingly.

Also received my ship notice from Buds earlier for my upper, should be here in a couple of days; I can't wait!

 

[bedlamite]

FYI, the Remington ammo has a reputation for being anemic and inaccurate.

It depends on your situation, but it is possible to mount a press to a board and C-clamp that board to a table/counter/bench, and I even used a Lee hand press for a short time several years ago. Where there's a will, there's a way.