AR-15 Accuracy to 600 yds

Ganderite

Ganderite

CGN Ultra frequent flyer
Rating - 99.7%
355   1   0
Location
Farm south of North Bay
I have enjoyed shooting F Class, but I find some guys spend more on their shooting rest than I do on my complete rig (a 260 Ackley).

For Shi*tz and giggles I am considering shooting the short range matches with an AR15. I have several, so could use one for an accuracy build.

My first inclination is a 20" heavy 1:8 223, shooting either 77 gr or 80 gr Sierra match bullets. The match requires single loading, so the OAL need not fit the mag.

With a bolt rifle I have used the 80 Sierra back to 1000. In fact, I once won a match with it. But I have no idea what kind of accuracy the 80 can get out of a AR-15. Velocity would be a lot less than the 3000 fps out of the 30" bolt rifle.

Would a 6.5 be a better choice for 600 yards? Anyone with any actual experience to share?
 
Last edited:
A good heavy barrel AR should shoot well. I had a Rock River Arms 20" that would hold very close to 1/2 MOA. I think you are on the right track with a good quality 20" heavy barrel. Personally, I would run a 69-77 gr bullet seated short enough that it would feed from the mag. Just me though.
 
Used in the US for competition back to 1000y.
Might not be competitive with a well handled F(O) bolt action rifle, but why not?
 
Red_Liner740 said:
If you have to load single bullet only as per match rules, I can't see the reason to use a semi firearm unless you already had it built.
Click to expand...

I can think of a number or reasons : the Hornady 75 A-Max , the Berger 80 VLD , SMK 80's etc

These projectiles approach the BC of 168Gr 30 Cal SMK ....and can be driven out at similar velocities
 
Last edited:
I would rather shoot a C7 at an Fclass match than a TR rifle at a service rifle match. More power to the OP.

The AMU/CMP used to have some really good tech articles online.
 
TRG-42 said:
I can think of a number or reasons : the Hornady 75 A-Max , the Berger 80 VLD , SMK 80's etc

These projectiles approach the BC of 168Gr 30 Cal SMK ....and can be driven out at similar velocities
Click to expand...

You can do that with a bolt rifle too eh. I think the OP is interested in trying something new. He's been there done that with competitive shooting. Why not experiment?
 
Bolivar said:
You can do that with a bolt rifle too eh. I think the OP is interested in trying something new. He's been there done that with competitive shooting. Why not experiment?
Click to expand...

Not sure why you think I am trying to imply you shouldn't use an AR ??

At any rate, to answer the OPs's question , there is no reason the SMK 80's , A-Max 75 or Berger VLD 80s won't shoot well

Depending how much you want to spend, you should look at a Krieger , Satern etc Cut rifle barrel if you are trying to eek out the utmost accuracy

I have a Satern 6.5 Grendel barrel that is boringly accurate

Having said that, if you won't want to spend that kind of $$ you can't go wrong with a Noveske stainless (they use their variation of Wylde chamber and Pac Nor blanks) , Rainier Ultramatch ( Shilen blanks ) , White Oak etc

Never had one of these barrels that were not sub MOA barrels

As far as your question regarding 6.5s such as the Grendel, on paper the 123gr Lapua Scenars have a significant advantage with BC but not sure worth the hassle over 5.56 / 223 . I have two similar builds of both 6.5G and 5.56 ( Mk12 style builds ) and can't really say that out to 300 yrds the Grendel has appreciable advantage . Never shot both side by side at over 300
 
Last edited:
The question was why use a semi if you single load. You answered because these bullets. My point was that those bullets can be used in a bolt gun too so it doesn't seem like a reason to use a semi.

I never meant to imply that you were saying the OP should use a bolt gun. Obviously he is asking about using an AR.
 
Bolivar said:
Why is 18.5 optimal and how is/was that determined?
Click to expand...

Kac did some extensive testing with regards to optimal barrel length and found 18.5 offered the most consistent whip/barrel harmonics with an almost zero loss of velocity.

Heavy barrels don't improve accuracy as much as many want to believe. Their claim to fame is heat dissipation and added weight for a more stable sight picture. The are more rigid that lesser diameter barrels but its of minimal gain.

Tdc
 
TDC said:
I presume so, I don't have all the details but kac doesn't offer a rifle longer than 18.5 and I don't believe they do heavu barrels.

Tdc
Click to expand...

They mostly use medium profile. Some of those are dimpled to reduce weight. The 16'' are thin and the profile only gets thicker (.75'') at the gas block. The 18'' LPR is medium profile but they use a stainless steel barrel.
 
TDC said:
Heavy barrels don't improve accuracy as much as many want to believe. Their claim to fame is heat dissipation and added weight for a more stable sight picture. The are more rigid that lesser diameter barrels but its of minimal gain.

Tdc
Click to expand...

That sums it up rather well. The quality (consistency) of the steel is the determining factor for accuracy.
 
You must log in or register to reply here.
Back
Top Bottom