Home Forums Hunting & Shooting AR and Tactical Rifles 6-6.8 feedback

I’ve decided after looking at the many options for a 6mm AR on doing a 6-6.8 upper. I don’t care much about the high BC 6mm bullets above 100 gr, I’m interested in hunting inside 500 yards. I’m also not interested in a Grendel type cartridge (6mm AR), I’d like to use the 6.8 bolts, magazines etc.

What is a real shame is that Constructor (originally of Black Hole Weaponry, and now running AR Precision) has a wildcat, the 6 TAC, which will even run the heavies up to the 105 VLDs. It has a bit more powder capacity than the base 6-6.8 and 30 deg shoulder. However, no dies are available and they’re needed to form brass. That one might be a SAAMI candidate...

So I’m back to the straight 6-6.8, which at least is nice in that it’s just a trip through a sizing die to form brass.

Is anyone running one? How has it done? I’m thinking 7 or 8 twist, and that it should hit about 2850 FPS with a 95 gr bullet out of a 22” barrel.

My plan is to get a 6.8 upper kit minus barrel, and add the barrel. I’d appreciate any thoughts on a good route there also.

Thanks, and I hope y’all are staying safe and reasonably sane!

Theres always the 6WOA and 6DTI as well.

I'd seen mention of both, but didn't do enough searching around the DTI. Thanks!

It looks like Dtech has 6 DTI dies, barrels and complete uppers, using Shilen barrels to boot. It's a bit faster than the straight 6-6.8, with a 30 deg shoulder. I'm still thinking 8 twist.

Matt at Dtech said a 22" barrel should break 3000 FPS with a 85 gr. TTSX. It doesn't leave room for the longest bullets, but I think the 87 or 95 gr Berger Hunting VLDs might work. Even the 100 gr Speer SBT should stay supersonic out to 900+ yards. It's all sounding pretty good to me!

Now to ponder the exact build...

I built a rifle on the TAC 6. It's still pretty new to me but I like it. Great accuracy, good speeds. I think if you are looking to shoot lighter bullets the 6 x 6.8 isn't that bad of an option. My understanding is, the shoulder on the TAC was set back and case shortened to better suit the longer heavier bullets. If the 6 ARC ever materializes it may solve most all of these issues, I think it is just set back .01" more than the TAC but that is just going off memory. I would think 8 twist would be plenty, as it stabilizes everything I've shot up to a 108.

Just a straight up 6x45 in a BHW barrel here.

It's about as simple as it gets for a 6mm AR.

Go to The Predator Masters and ask about the 6-6.8. It seems several of the shooters are using the 6-6.8 and are really liking it. Go to the AR forum and ask about it there. You will have to join and log in.

http://www.predatormastersforums.com/forums/ubbthreads.php

A google search will send you to many different web sites that discuss different 6mm AR15 options. Sniper's hide, Arfcom, etc. When I was deciding which one to get I went to those sites and researched the options. I settled on the 6WOA, as it has been used in competition and has proven to be very accurate. Its a well designed cartridge and is very simple to load for. You can run new 6.8 SPC brass through a fl sizing die and you are good to go. It is very simple and there are no extra steps required. I've found that accuracy is quite good, even with brass that has not been fireformed to the chamber or "once fired".. I've been very impressed with the 6WOA cartridge and have fired it from 100 yards to 450 yards. It is a great shooter near and far. I have settled on the 85gr sierra gameking bullet, as I can use it for hunting as well as some target shooting and practice. I think the op is looking in the right direction, as I believe the 6-6.8 is very similar to the 6WOA. Here are some accuracy results from my 6WOA:





Here are some velocities I was getting with AR comp powder and the 85gr SGK:


When I first started looking for a 6mm that would fit in the ar15, my first thoughts were to just get a 6x45, but then I found a 6WOA locally and decided it wouldn't be a bad thing to buy a 6 that would produce faster velocities and one that was made to shoot. John Holliger from WOA actually uses the 6WOA for competition. I think the OP is on the right track with his thoughts on twist rate as well. Mine is a 1 in 10, I believe and does not like bullets that are over 90 grains. I tried the 90gr gamechanger and shot patterns, not groups. The 87gr v-max is also a very popular bullet for these 6mm cartridges and one that my 1 in 10 will stabilize surprisingly well.. What the OP will find is most of these 6mm cartridges are very similar. However, some may have better support than others. In that you can easily find die sets, barrels, and other parts and even load data. If I were to do it again, I might consider the DTI or 6-6.8, as they are just peas in a pod.

That does sound pretty promising. Stick to your guns on the 1 in 8 twist, as my 1 in 10 does not stabilize the 90gr gamechanger, which I admit pizzes me off...

Sorry to hear the 10 twist isn’t shooting the Gamechangers, that’s a bit surprising to me. Almost all 10 twist 243s should shoot that OK, albeit at 10% higher velocity. I’d try some other bullets in that weight range like the 95 gr. Ballistic Tip, and even the Speer 100 gr. SBT which is fairly short and really cheap! ;-)

Your rifle shoots very well, I hope mine ends up in the same ballpark!

(BTW the 6 DTI is also just a single sizing operation to the 6.8 brass.)

Thanks again for the info and pointers!

I have a 6dti. If doing it again I would go with a 6mm Hagar. The stylish thing is is keep witiling down the 6.8 case till it’s no more than a 223 case. Or 22 nosier. Even more interesting would be a 20 nolser

Here is a little reading on the subject:

Differences of the 6WOA, DTI ,6-6.8 and Hagar

I've been messing with my iron sight Noveske a lot lately, but this talk about the 6-6.8 makes me want to shoot my 6WOA. I have some 87gr v-maxes and berger's to play around with too. The guy I bought it from said they worked very well through this WOA, using IMR8208XBR. I don't care for that powder, but will play around with more AR comp and this WOA when I get a chance..