AR-15 Build, Seeking Advice

[WestTex]

Hello Folks;
I'm looking to build an AR-15, but trying to get started makes me more confused as I continue to read and try to understand exactly what parts I need to be searching for. Too many acronym's that I do not yet understand, a bazillion choices of part manufacturers, what fits what, etc. "Oh my aching head!"
What I am seeking is long range accuracy, as well as projectile fragmentation velocities still remaining at up to 500 yards out, if this is possible. I'm not looking for a competition 'match' rifle. I'm looking for something that will hit pesky fur bearing targets made of meat.
I'm thinking a 20" barrel with a 1:7 twist, shooting 77 grain bullets. I could be way off on this, not sure. Am I on the right track, or what? Please chime in and educate me!

 

[NWcityguy2]

I shoot my AR quite a bit, but 300 yards is the furthest distance I'd trust myself to hit an 8" target on the first try. 500 yards hunting with a 223 is quite a distance. Why not go with a bigger caliber in a bolt action rifle? Certainly at that distance performance would trump a fast follow up shot.

People who shoot ARs at a distance more use them because 223 is cheap, has low recoil and it is a good test of skill. Terminal performance isn't part of the equation.

 

[1911 guy]

You're pushing it asking for fragmentation at 500 yards. Everything else is doable (assuming your marksmanship is also up to it) with a decent barrel and free float tube.

 

[rskent]

I'm thinking AR10

 

[Tirod]

Fragmentation is the province of FMJ military ammo. What you need at 500m on varmints is expansion, and there is civilian ammo that does a much better job of it. Look to Black Hills 77 TMK.

As for build advice, you have a clear plan - it just needs to be walked thru. A long range varmint is going to be a flat top A3 upper with 20" barrel, rifle gas, free float with NO integral rails. A good scope would have to mount on the upper receiver regardless, you can add a strip under the float for a bipod.

The stock and grip are up to you - something adjustable with a good cheek rest but not a heavy "sniper" grade. Add a good trigger. All the smaller parts at least GI spec, the confusion with aftermarket parts is that they are trying to pry your cash from you while promising great results. Spending 5X more for a charging handle or exotic billet means you spent 5X more - you never get 5X more performance or accuracy.

Since the build is long range varmint - you only look at the long range suppliers, and you only consider the long range parts that you know will deliver.

 

[Blade First]

"Fragmentation is the province of FMJ military ammo. What you need at 500m on varmints is expansion, and there is civilian ammo that does a much better job of it. Look to Black Hills 77 TMK." -- Tirod

Shooting small furry things at that distance should not require expansion. Fragmentation, unless you are handloading at extremely high pressures, is out of the question. Many ammo makers offer heavier bullet-weight rounds which you'll need to hold supersonic velocities at that range. Black Hills is a good choice as is the line of TAP from Hornady, especially their 75g, polymer-tip load.

"As for build advice, you have a clear plan - it just needs to be walked thru. A long range varmint is going to be a flat top A3 upper with 20" barrel, rifle gas, free float with NO integral rails." -- ibid.

Choose a bull-barrel in the 20-24" range as it doesn't sound like you're going to want to haul your rifle around in the woods. Lots of choices available in mid/rifle length gas tube versions. Using a good quality muzzle brake will let you see bullet strikes thru whatever glass you choose. Will be like shooting .22lr given the overall weight.

Choose a quad-rail free-float tube so you'll have plenty of options for accessories...most importantly for a bipod stud adapter.

"The stock and grip are up to you - something adjustable with a good cheek rest but not a heavy "sniper" grade." -- ibid.

If you shoot up to 500 meters you'll want a multi-adjustable stock. Magpul would be an excellent place to start.

"Add a good trigger." -- ibid.

Since this is clearly not what is intended to be a 'working' gun, I'd be inclined to arrange a crisp pull weight of 2.0-2.5 lbs. Have had great success with ALG parts and JP Enterprises spring kits.

"All the smaller parts at least GI spec, the confusion with aftermarket parts is that they are trying to pry your cash from you while promising great results. Spending 5X more for a charging handle or exotic billet means you spent 5X more - you never get 5X more performance or accuracy." -- ibid.

Simplistic, at best.

"Since the build is long range varmint - you only look at the long range suppliers, and you only consider the long range parts that you know will deliver." -- ibid.

Accumulating excellent parts from any number of suppliers is guaranteed to result in a premium-quality rifle. Isn't that what you want?

 

[Jackal]

Spend about $300 on a good barrel, $130-$150 on a trigger and the rest is gravy.

 

[crazysccrmd]

Choose a quad-rail free-float tube so you'll have plenty of options for accessories...most importantly for a bipod stud adapter.

What accessories, other than a bipod, do you need to attach to a varmint rifle? A quad rail is heavier and bulkier and just unnecessary. There are any number of better choices, from a simple tube to the various keymod/mlok hand guards that allow precise placement of rail sections when needed.

Compare a lightweight varmint bullet to the heavy 77s and see what it looks like. I'm not sure if they will hold up at range but the added velocity and light construction will do work on varmints.

Another option might be something other than a 5.56, especially if you're a reloader. A 204 Ruger, 20 Practical, 22x6.8, and other might do a better job with long range varmints.

 

[WestTex]

I'm reading lots of good information here, and soaking it all in. That being said, I'm having mixed thoughts, now. AR-15/.223 vs. AR-10/.308. I'm no stranger to the .308 when it comes to long distance accuracy, however. I'm growing a bit long in the tooth, per se, and not so sure that I care for the 'thump' delivered by a .308 when pulling the trigger. Might knock my dentures out if using a beefy round! Last thing I want is to harvest a dead critter that has a sarcastic smile locked to its face from laughing its ass off just before my bullet hits its mark! .223 is a bit questionable, although still lethal at medium range shots if the weapon is built correctly, but it's still a .223.

What are your folks thoughts about 6.5mm?

 

[Blade First]

"What are your folks thoughts about 6.5mm?" -- WestTex

One of the best 3-gun competitors in the Southeast is quite happy with the performance of the 6.5 Grendel on really long-range stages...plenty of weight in a long-shank bullet with a high ballistic coefficient.

Extremely versatile...will handle everything from prarie dogs to moose.

 

[David4516]

How about .25-45 Sharps?

I have zero experience with it, but on paper at least it looks cool...

http://www.americanrifleman.org/articles/2014/4/17/the-25-45-sharps-a-new-old-cartridge/