I’ve been looking at a few new calibers for hunting and the 6.8 crossed my mind. I’m not familiar with the 6.8 and did a little lurking on the 68forum but was wondering if someone could give me a quick education and hints on what I need to be looking for.
What barrel length? I was looking at 16". Does the 6.8 burn the powder fast like the 300 blk, where a short barrel would work better and not much benefit on longer barrels, or is it like the 6.5 and need the most length. I see a wide variety of barrel lengths. I didn’t know the loss or gain of fps/inch of barrel. I have a few SBR’s so if shorter is better then that’s okay.
Twist rate? Would like for it to shoot the 120gr Hornady SST.
3.Mid or carbine length gas system (That would relate to barrel length and powder burn rate, which again I know nothing about the 6.8).
4.Best magazine?
5.Best Bolt (does the 6.8 have bolt breakage like the ar15 in 7.62x39)? Are the BCG and Bolts compatible where I can swap it out.
Optimal port size? I do not want one that’s over gassed.
Please just give me the quick throw down on my questions so I can have a little info while I am doing more research. I have been pondering the idea of buying a complete BCM upper and just swapping the barrel, BCG and bolt. This would be shot only suppressed with supersonics for hog hunting. The AR-10 is just too heavy once everything is mounted and long walks.
I bet my questions are common knowledge in the 6.8 world. Thanks for any info.
-Ryan
Barrel length: 16" is just fine. The 6.8 was designed to be ~50% better than 5.56 out of 14.5" barrels and in reality does great even out of shorter barrels than 5.56. Only real reason to go longer is to squeeze as much juice out of it as you can.
Twist rate: 1:11 is the current standard. HOWEVER, more importantly is the chamber spec, make sure it is spcII (don’t even know if you can still find the original spc chambering without purposefully looking for it, but something to be aware of none the less). Just like the 5.56 though, a tighter twist rate is not necessarily a bad or detrimental thing, unless you shoot some extremely light weight fragile bullets.
Gas system: Same story as 5.56. Carbine works but Mid length will be easier/softer in general on the weapon and the shooter.
Magazine: ASC and C Products Defense have great prices and reliability. They will also allow for a longer COAL if you intend to reload and go long.
BCG: You will need a 6.8 specific bolt, carrier is the same. I use a Hamlund Tactical NiB BCG, there are other reputable manufacturers as well such as Stag Arms and AR Performance. Bolt breakage is a non issue for the 6.8, same lifespan as 5.56.
Gas port size: Beyond my knowedge.
You should head on over to 68forums.com for as much info as you can handle by the resident experts there.
I’ll just agree with ColtSeavers here. Go to 68forums and look for the thread titled “Hints, Tips and general information”. Plus you can always ask the people there. I recommend that you do a little reading of threads first, tho. Some people have gotten tired of being asked why they can only fit 5 or 6 rounds of 6.8 in their 5.56 magazine…
Do a lot of reading first. I jumped on the 6.8 early and fizzled out quickly. I eventually sold off my upper, mags and ammo. The juice just wasn’t worth the squeeze for me, YMMV. Do some research and see if that is really what you need.
ColtSeavers,
As for the SPC and the SPCII chamber, I remember reading a few years ago about the Remington dilemma over the chamber and thought all manufacturers switched to the SPCII or their form of the SPC chamber. Just SAAMI has not updated their loading data. Thanks for the Info.
USMC Anglico,
I am looking for something with a little more power than the 556 but just want to try something new since I have plenty of 556 uppers. Ive been hunting with 300 blk sbrs and am impressed with the stopping power on pigs with them, but Ive read the 6.8 is even more powerful and better for long range.
Maybe “Constructor” will reply and give some information about the port size and what would work for suppressed.
I went with the proprietary Six8 system by LWRC. I liked the fact that they designed a magazine in conjunction with Magpul and then built the gun around it. I have a 14.7" SPR which is in transit as I type this on its way back from the factory, where they installed a 16" spiral fluted barrel, an adjustable gas block, and a muzzle adapter for my Saker 7.62 suppressor. I get it back on Monday!
I also have a Six8 pistol, which I am SBRing. In both cases, the platform has been remarkably accurate and significantly softer shooting than a 308 AR. I recommend it not just as a hunting round but also for self defense.
I love the 6.8 for hunting…
Been running them for about 7 years…
killed a LOT of deer and hogs
The others covered the tech stuff fine.
I have ran just about every bullet and ammo option out there and have been running the 120 SST the last year.
It just puts them down fast.
I live in Texas and we do a ton of hog hunting, I know several guides that have tested the 300 Blackout and all say the 6.8 clearly works better.
Building my 11 year old a 6.8 right now, he dropped several deer in their tracks with my 6.8 and him and my older son both lost deer last year with a 300 BO.
Confidence is king
I have been using a 6.8 spc (not II) since 2012. I have plenty of use out of this rifle. It is a 16", carbine length gas, olympic barrel.
I like this caliber because it can reach out a ways, and has plenty of knock down power. I have killed hogs with it. I am using your questions:
1. What barrel length? I was looking at 16". Does the 6.8 burn the powder fast like the 300 blk, where a short barrel would work better and not much benefit on longer barrels, or is it like the 6.5 and need the most length. I see a wide variety of barrel lengths. I didn’t know the loss or gain of fps/inch of barrel. I have a few SBR’s so if shorter is better then that’s okay. - I run a 16" carbine length. That works just fine. I also have a 6.8 sbr. I guess length all depends on what your main goal is for the rifle? plinking, hunting, etc…
2. Twist rate? Would like for it to shoot the 120gr Hornady SST. My spc has a 1/10, my buddy’s spc II has a 1/11 twist. Both rifles shoot 120 ssts just fine.
3.Mid or carbine length gas system (That would relate to barrel length and powder burn rate, which again I know nothing about the 6.8). Either gas system will be fine, but mid length should tone the recoil down a bit. If its an sbr, that will also come into play if you are using a supressor. Again, what is the purpose of the rifle? hunting, plinking, etc…
4.Best magazine? I use AR stoner and ASC mags. I hear a lot of good things about PRI mags but never used them.
5.Best Bolt (does the 6.8 have bolt breakage like the ar15 in 7.62x39)? Are the BCG and Bolts compatible where I can swap it out. 6.8 has its own bolt. I have never broke a 68 bolt…I have used olympic, stag, and rock river…all seem fine.
6. Optimal port size? I do not want one that’s over gassed. - I would ask Constructor - he has helped me a lot with my questions on the 6.8.
I just bought a YHM 6.8 marked upper from a friend for $90.00, got a wilson combat LW SS barrel 6.8 barrel on a recent sale they had, a Gas block, gas tube, KMR 13 inch rail, a cheap 308 flash hider, stag 6.8 bolt/carrier group and it seems to work fine, shoots reasonable with Hornady 110 grain Vmax’s, I have one magazine but am ordering a couple of 10 round PRI’s. Shoots OK 1-1.5 or so for 5 with those bullets. I am going to reload for it, I have a box of 110 grain Barnes TTSX probably too heavy but it is what I have.
1 I have 2 6.8 one 11.3" Wilson combat and 16" ar-15 performance. Both are Moa or better. I don’t have chrono so I am not sure what my fps are with hand loads.
2 I would stay with 6.8 spc ii and 1/11 twist. My16 loves the 120 hand loads and factory 120s. The 11.3 not so much it loves the 110gt v-max
3 the 16" is a mid length and 11.3" is carbine.
4 I use c-product I would stay with the metal mags
5 my 16" was sent with a matched bolt. And I use the same bcg and bolt in the 11.3 with no issues. Also the bcg is the same as the 223 all you need to do is change the bolt. I have t had any bolt breakage
6 probably 750 I like the adjustable gas blocks
I like shooting my 6.8 probably better than my 5.56, it is a blast. I used the barrel from ar15performance and it is an MOA shooter for sure. I finally broke down and bought some Barrett mags but have yet to try them. The ASC and C-products both have worked fine in my gun. Good luck and have fun. For most of your 6.8 stuff just talk to Brett at Ironworks Tactical. Super nice guy and very knowledgeable.
I bought six of the Barrett metal mags back when I first got into 6.8. While they have seen some woods use, its mostly been range; but they have been flawless. They’re well constructed, and they hold 30 which I prefer.
