I just recently got in to the ar world, and i have a friend that wants to go out and shoot P-dogs this summer, he tells me that he has a 6.8 ar and his rifle will do MUCH better at 200-300 yds.  I cannot find much info about it on the web so i decided to ask if i would be out gunned at 200 to 400 yds just comparing guns to guns.

He is running a stndard 16" ar with a 3-9 X 40 rifle scope on it.

I have an ar variment rig set up with a blemished lower reciever from RB and a full 20" variment kit from model1sales.  and a 6-24 X 50 variment scope. i am running 223/5.56 ammo


is there any rational way for him to be talking smart??

Thanks

Quoted: I just recently got in to the ar world, and i have a friend that wants to go out and shoot P-dogs this summer, he tells me that he has a 6.8 ar and his rifle will do MUCH better at 200-300 yds.  I cannot find much info about it on the web so i decided to ask if i would be out gunned at 200 to 400 yds just comparing guns to guns. He is running a stndard 16" ar with a 3-9 X 40 rifle scope on it. I have an ar variment rig set up with a blemished lower reciever from RB and a full 20" variment kit from model1sales.  and a 6-24 X 50 variment scope. i am running 223/5.56 ammo is there any rational way for him to be talking smart?? Thanks

Your buddy is full of shit.

The ballistic coefficient (barely .35) of the available .277" bullets that fit in the 6.8 SPC, plus the meager muzzle velocity he will get with a 16 barrel (barely 2500 fps) are NO match for a quality 223 load using the Hornady 75 gr or Sierra 77 grain match bullets (BC of just under .4) at the 2700 fps that you will get from a 20" barrel.

If the 6.8 SPC were so much better ballistically, highpower match rifle competitors would be rushing to rechamber all their 223 AR match gun to 6.8.  But they are not.

Any good highpower shooter using 75 gr 223 ammo would own your buddy using his 6.8 at 300 yards and beyond.

i seriously doubt you will be "outgunned" since there is a wider variety or ammo for the 5.56 than the 6.8

you can also shoot the 5.56 all day or all week long without having to  worry about what you are going to do for ammo after you are done.

kinda what i thought,but there is always the guy who knows everything and is right about half the time.  and i try not to challenge him unless i have the opertunity to prove him completly wrong.

where doi find a chart for ft lbs of energy on the web so i have proof that we are not going to be lopsided

Quoted: where doi find a chart for ft lbs of energy on the web so i have proof that we are not going to be lopsided

You guys are going to kill prairie rats.  What does it matter how much more KE does the 6.8 deliver?  Both have enough energy to blow a dog to pieces if hit squarely.

In any case, a 110 gr .277" bullet shot at 2500 fps reaches 300 yards with 809 ft-lbs of energy, while a 75 gr .224" bullet shot at 2700 fps reaches 300 with 736 ft-lbs, based on my Sierra Infinity ballistics software.

Show him this....

Prairie Dog Hunt

That may end the discussion

or this.....

Prairie Dog Gun

See ya in the fields....

Quoted: Application, folks, application! For shooting at prarrie dogs, the 5.56 is generally the better choice, because it has more appropriate bullets available for it.  NOTE: the last thing you want for hunting p-dogs is a 75-77gr bullet; think 50-60gr VMax or BlitzKing. The 6.8 SPC was developed to be a COMBAT load, and it is excellent at that (and coincidentally, excellent for hunting medium-sized game like deer and hogs), but its strengths aren't as apparent when hunting p-dogs.  Varmint-sized animals are really what most 5.56-class ammo is best at. -Troy

EXACTLY. The Ar with varmint loads should give far superior visual results compared to the 6.8.
You'll both get dead dogs, yours will just explode more.

That said, get a high quality match upper and start shootin out to 600 yards and see what happens between his 6.8 and your 556.......