6.8 and extra distance

[Builder Bob]

So I am thinking about building a rifle and was considering 6.8 for caliber. I am wondering if anyone has looked into stretching the effective distance? I was trying to stay in the ar-15 format and not stepping up to the ar-10 (.308).

So if I increase the barrel length(vs standard 16" carbine), how much would that increase range? Would it be better to look at the 6.5 instead? I think would like to stick with 6.8 since it appears to be the more popular caliber at least right now.

FYI, The primary rifle purpose would be hunting and long range target shooting.

Any thoughts or suggestions would be appreciated

[Links2k]

Check out www.68foums.com. Lots of good info and good people.

[Links2k]

From what I have heard the 16" barrel is optimum for all of the uses that you mentioned.

[Guest 6.8 AR]

You might have more problems finding Grendel ammo. don't know for a fact.

How long range for target shooting? 6.8 will shoot with a 5.56 with some more

energy. 16" is plenty of barrel for 6.8. There are a few 18" barrel suppliers out there.

Bison Armory had some and are good barrels.

[Builder Bob]

I was thinking about trying to get out to 5 - 600 yds. It might be best with a bolt gun for there and beyond but just getting started with the thought process between 6.8 or ar-10/308 etc. in a semi auto.

[50 cal]

When I was at Barrett, we built some 20" barreled uppers in 6.8 for the USMC to be used as DMR styled rifles. The accuracy was amazing. We only shot them out to 500 meters before shipping to Quantico. The Corps liked them and ordered more.

Wished I would have bought a barrel at that time. I use a 16" 6.8 and like it. Does what I need. Don't shoot it past 300 meters. Don't have anywhere to stretch it out past there in the Knoxville area.

[Jonnin]

You might try to make some longer range ammo for it. A mid-weight bullet with a hefty loading, maybe, experiment and you might find a way to get a bit more range. Its still only going to go as far as it does; at some point thats all you can do in the given caliber. A longer barrel may also help. Bullet style will help too, some designs carry farther and more accurately. I would attack the ammo side first, see how much you can get from just that, as its easier to do than finding the ultimate barrel, and I would think that 16 vs 18 inches will only have a very small effect, you want to really kick up the range you need to add a lot more than 2 inches to get enough velocity to matter.