6.8 SPC Build

[TNMTBik3r]

I have mentioned it a few times, but my next AR is going to be a 6.8 SPC ii. Looking for anyone here who has a 6.8 and any suggestions or thoughts you may have.

I already have the lower (PSA lower, LaRue MBT-2S 2 stage trigger, VLTOR Emod stock is on the way).

For the upper (Anderson upper receiver) I believe I am going with a Bison Armory 18" SPR barrel. May grab an AR Performance barrel if I catch them in stock starting January. I am not against a 16" barrel, 18" *may* be slightly more accurate, but from all I have read 6.8 excels in short barrels so just depends on what I find in stock.

Plan on a 13" rail, either Diamondhead VRS like I used on my pistol or a keymod of some brand.

I may get a matched bolt with the barrel. Otherwise just a 6.8 BCG from Aim Surplus.

I orderd 100 rounds of SSA 100gr Accubond ammo from PSA the other night. I have 250 new, primed FC brass ready to load. I need to find an inexpensive plinking bullet, possibly some Gold Dots from Rocky Mountain Reloading unless I find something cheaper. Also need to research powders more, looking through my Hodgdon/Hornady manuals the only listed powder I have experience with it Benchmark.
Probably go with Accubonds, Hornady SST 120gr, or Sierra Gamekings for hunting depending on the accuracy I get.

I am on the 6.8 forum and have read / am reading up more.

Anyone here have experience with 16"/18" barrel and your thoughts? Reloading bullet and powder suggestions?

[Bad_Bowtie]

I had a 20" stag 6.8 upper that I really liked but it was just too heavy for my taste. I'll probably replace it with a 16" soon. Bison and ARP are both great choices.

[173rdABN]

I've had a couple 6.8's from a bolt gun to gas guns. My last one I sold was a LWRC m6a3. I love that round. Loved reloading for it. But I got out of it because I could reload 308 cheaper so I just changed everything over to that.

The round is amazing. I truly love it. My LWRC was a 14.7" and to me the perfect length. Still got great velocity through it. The bolt gun was nice because I could load up heavy rounds like the 140grainers.

Anyways you'll like the round and can't go wrong with either barrel length. The round was designed to be shot from a short barrel anyways so that says a lot right there.

Again only reason I got out of it was it was just cheaper to stick with all 308 bullets for my 300/221 and 308 and loading for both was considerably cheaper. I'm sure things have changed since I was in the game of 6.8 though. Hell I started in 2007 with that round. So it's been a bit.

[173rdABN]

Oh yeah. I think I've used 1680, 322, 335, wc844 and a couple others in it. I MIGHT have my data laying around. I can check Monday when i get home. 322 was probably my favorite.

[leftyk82]

I've built two 6.8's and enjoy them both. One is a 16" SPR and the other is a 11.5" SBR.

Most accurate loads for me shooting 110g Hornady HPBT and 115g Sierra MK HPBT bullets are with AA2200. I think you'll find that's the go to powder from the fine folks at 68forums

My 16" barrel is from White Oak and shoots 3/4 MOA. My 11.5" is from Bison, currently loading up some 180g subsonic loads for it. The 180's will stabilize with its 1:7 twist.

Edited December 25, 2014 by leftyk82

[Smith]

Being that I loathe the 5.56, I've had several 6.8's going all the way back to the Kotonics days. Ended up selling them because I didn't reload and SSA was they only ammo maker and they were always out. You can't go wrong with the Bison or ARP barrels and bolts. I just built another one since you can actually get factory ammo and they have figured out how to make mags work.
I have yet to find anything negative about 6.8. Edited December 25, 2014 by Smith

[leftyk82]

Being that I loathe the 5.56, I've had several 6.8's going all the way back to the Kotonics days. Ended up selling them because I didn't reload and SSA was they only ammo maker and they were always out. You can't go wrong with the Bison or ARP barrels and bolts. I just built another one since you can actually get factory ammo and they have figured out how to make mags work.
I have yet to find anything negative about 6.8.

 

great point about the mags.  I've only bought and tried PRI and they work for me.  

[Smith]

great point about the mags. I've only bought and tried PRI and they work for me.

Evidently, PRI is closing out their ribbed/waffle version mags and coming out with a gen 2(?). You can get the old waffle ones relatively cheap right now. On the 6.8 forums folks really like the ASC mags. I also picked up some D&H mags really cheap at PSA and they work well. Heavy but good none the less.

[TNMTBik3r]

I planned on PRI mags. Saw the D&H mags, they have worked well in 5.56 for me so may try some 6.8.

I may end up going with a 16" barrel since the round does work so well from short barrels. An 18" may be slightly more accurate but doubt I will notice, as both brands I am looking at seem to be consistent sub-MOA barrels regardless of length.

Thanks for the powder info. The only one listed in my manuals I have experience with us Benchmark and it meters great. Will need to read up on the others, prefer to use a ball powder instead of extruded.

[leftyk82]

I planned on PRI mags. Saw the D&H mags, they have worked well in 5.56 for me so may try some 6.8.

I may end up going with a 16" barrel since the round does work so well from short barrels. An 18" may be slightly more accurate but doubt I will notice, as both brands I am looking at seem to be consistent sub-MOA barrels regardless of length.

Thanks for the powder info. The only one listed in my manuals I have experience with us Benchmark and it meters great. Will need to read up on the others, prefer to use a ball powder instead of extruded.

 

I was sold on the 18" at first also, but when I saw the velocity numbers between that and the 16", I decided the maneuverability and weight savings was enough to offset the 50-100 fps loss.

[173rdABN]

I always used Barrett mags and literally never had a problem with my gun. I loved those mags.