Is there a link someone may be able to provide (or may know the info off hand) to determine the ideal barrel length for a 6.8spc? I have a spare carbine bushy I want to convert. While I am not a hunter, I may possibly end up getting asked in the near future. I don't own any hunting rifles aside from a 30-30 and frankly don't like it. I had a few bolt action 30-06 rifles but also did not like them. So I thought and AR with some balls would work should the need arise. I like the 6.8 because after a barrel and bolt, I am good to go. Just don't know if I should opt for a 16" or 20". If I used a 16" I could use my carbine handguards/gas tube/etc.

If you don't have 6.8mm SPC mags from PRI... you won't have shit.

I will go ask Zak-Smith on barrel lengths for your lazy northern ass, though.  

Quoted: If you don't have 6.8mm SPC mags from PRI... you won't have shit. I will go ask Zak-Smith on barrel lengths for your lazy northern ass, though.

Thanks REDNECK

Quoted: Quoted: If you don't have 6.8mm SPC mags from PRI... you won't have shit. I will go ask Zak-Smith on barrel lengths for your lazy northern ass, though.   Thanks REDNECK

Roger That.  

You have RR's data... kinda twilight zonish like different barrels can be.
I'd go 16" with RR's data.

Zak said, "The difference between a 16 and a 20 should be in the 120-140 fps difference, RANGE."

Using only Zak's input, I say:
Since I am low-speed/high-drag, I'll take the extra velocity along with the extra 4 inches of barrel.  The 120-140fps represents a 60-70% approach to magnum rating.  That's alot for no extra powder, less recoil, and a very little increase in weight.  Ahh, how 'bout an ABS barrel, hmmm?

I have been humping both an AR-10A4 and AR-10(T) when deer hunting for the last 7 years.  The first five with a herniated L5/S1 disk and the last two with a ruptured L5/S1 disk.  A 20" AR-15 platform will be cake, coffee, and a fine cigar.



From my journey in the 6.8 realm of scoping out others' chrono data with their barrel lengths... I'm going with a 20" tube.