6.8 SPC

[Maelstrom]

So earlier this year I bought a Palmetto State Amory complete upper https://palmettostatearmory.com/psa...l-15-lightweight-m-lok-upper-with-bcg-ch.html for a hog gun project. I know it is PSA but it was in stock and could get me ready for my trip in January. Well this thing shoots like crap. I am barely holding a 7-8 inch group at 100 yards with Hornady Factory 110 gr vmax. I have tried both the black ammo and regular 110 gr ammo. Sellier & Bellott factory holds about a 4-5 inch group. I have a new barrel on order from Craddock Precision that should be here around April or May. I pulled the upper apart when I received it and went over everything. Nothing stood out as wrong. I made sure everything was torqued properly and had a buddy double checked the headspace. Everything checked ok. I am running a Bushnell LRHSi in a Seekons MXM mount. After shooting I double checked and they are torqued tight. Pulled the mount and put it on another rifle and shot good groups so I know it's not the scope or mount. Any suggestions or ideas what do do next? I am wondering if the 1/11 twist rate is causing the problem. I hope not because I have almost 500 rounds of each of the Hornady ammo. The barrel I order from Craddock is 1/10 twist.

 

[346ci]

With that many types of ammo, I'd say the barrel if everything else is tight. I'm not a fan of cheap psa stuff either.

AR15 Performance is the industry standard for 6.8, excellent barrels for the price.

16" 6.8 3R 11 twist Scout barrel-

www.ar15performance.com

 

[blackblue]

It's not the twist rate, likely just a junk barrel. Bison and ar15 performance like stated above are go to.

 

[Molon]

The 110 grain V-MAX never did much better than 2 MOA for me (still much better than your barrel is showing though). Give the 115 grain Sierra MatchKing a try.

30-shot composite groups at 100 yards . . .

10-shot group at 100 yards . . .

...

 

[Maelstrom]

The 110 grain V-MAX never did much better than 2 MOA for me (still much better than your barrel is showing though). Give the 115 grain Sierra MatchKing a try.

30-shot composite groups at 100 yards . . .

10-shot group at 100 yards . . .

...

I will see if I can find some. The 110s are all I have seen in over a year. Anytime I could find a box I would grab it. I have dies on backorder and on the lookout for powder.

 

[Maelstrom]

It's not the twist rate, likely just a junk barrel. Bison and ar15 performance like stated above are go to.

Didn't think about Bison. I ordered the barrel from Craddock Precision about 4 months before I bought the complete upper.

 

[Quiet6.8]

For Hogs, I’d check out CavityBackBullets. They custom load at +P SPCII chambers, more particularly for the ARP chamber. They have 105 & 120 solid copper bullets designed for 6.8 speeds. They group under MOA with my 16”ARP barrel with a 2.5-10 NF. While I have not harvested anything yet with the 105s they are my go to bullet for Mulies

 

[Maelstrom]

I have looked at CBB bullets before. There loaded ammo was out of stock at the time. I will order a couple boxes to see how they shoot.

 

[Mike_in_FL]

Did you contact PSA? I'd think they'd want to let you return it.

 

[Maelstrom]

I called them the day after I shot it. Unfortunately because I painted the gun and swapped the gas block to a superlative arms gas block they are saying I voided the warranty.

 

[diggler1833]

In my limited experience, I did not have the same luck with accuracy in the 105gr CBB in my 6.8 as I did with other bullets. However, my load development was extremely brief. Keeping distances under 100 yards I had no problems killing most everything I shot at, even though my accuracy was about 2 MOA, mostly vertical. For reference: my rifle is an Ambush Arms and is 1 MOA or just a hair better with several other loads.

The MKZ bullets work very well on hogs, highly recommend...much more so than I'd ever recommend a V-MAX.

I hope that your Craddock barrel gives you what you're looking for.

 

[Maelstrom]

Thanks @diggler1833 I was originally going through route of a quality build but with the delay 9n the barrel I figured I would try the PSA upper. Lesson learned I guess. I went ahead and ordered some CBB ammo. 4 boxes of each to try. I am going to give them 5 rounds for each bullet and see if it makes a difference. I really don't expect much from the PSA upper at this point. I leave in 3 weeks to go on my hog hunt for this year. Unless the CBB ammo surprises me I will be leaving the 6.8 at home and sticking with my AR-10 .308 and 5.56 again.

 

[diggler1833]

Thanks @diggler1833 I was originally going through route of a quality build but with the delay 9n the barrel I figured I would try the PSA upper. Lesson learned I guess. I went ahead and ordered some CBB ammo. 4 boxes of each to try. I am going to give them 5 rounds for each bullet and see if it makes a difference. I really don't expect much from the PSA upper at this point. I leave in 3 weeks to go on my hog hunt for this year. Unless the CBB ammo surprises me I will be leaving the 6.8 at home and sticking with my AR-10 .308 and 5.56 again.

I found something interesting out when I switched back to the .308 a little while ago (temporarily): The .308 with a cheap soft point bullet is neck and neck with the 6.8/Grendel and a premium bullet...as far as *my* number of hits to recovered hogs is concerned.

However, the hydrostatic shock is greater with the .308. I dropped several more hogs right on the spot with hits to the heart area with the larger cartridge. It still happens with the smaller cartridges, but is less frequent or predictable.

Still, I was quite surprised at the potency of the 6.8 and Grendel with a good bullet. Those CBB will be excellent if your rifle likes them.

I switched back to the .308 for a bit because reloading for it was saving me 40-45 cents per shot. Hard to argue with good terminal performance in a 26 cent bullet.

I'm looking forward to seeing long-term how the .308 and 6.8/Grendel stack up with identical bullets. I have SSTs and lightweight TTSXs for all three.

Unfortunately it is going to be a bit. Shoulder really took a shit on me, and I'm waiting for surgery now through the VA. Getting out is difficult at the moment.

Good luck on the hunt.

 

[Maelstrom]

Thanks. 2 of the guys I hunt with have been pushing for me to get a 6.8 or .300BO for a couple years. I have been running my AR-10 .308 for 3 years now. Before that I ran a bolt gun. 22-250 or 5.56 AR. The .22-250 never failed to stack them up. Head shots dropped them on the spot out to about 350 yards. 5.56 I kept to under 100 yards and even then we failed to recover a few over the years. Last year dropped 3 with the .308. The biggest was just over 250 lbs. The other 2 were between 140 and 180 lbs. I still want try and whack one with my .338 LM just for shits and giggles. One of the older guys John runs a .270 bolt gun and my buddy Aaron bought a Nemo .300WM for this years trip.

 

[Smokin7s]

We shoot a lot of them right behind the ear and in the shoulder and ribs with the cheapest shittiest 5.56 fmj we can find and get along pretty good.

 

[Ridge_Walker]

Like to reinforce the recommendation of those that said ARP (AR15Performance) barrels are the best. Don't about know about Bison personally. Have 5 ARPs though.

Also this thread here is something you should read before you put a new barrel on.