Am I missing something?

[KnotRight]

Want to build an AR-15 in 5.56 with a 20" barrel but they are very hard to find without coming close to the $400 mark. Should I reconsider the 20" barrel? Was hoping to play around at 4 to 500 yards.

 

[Ikarus1]

Well, accuracy doesn't depend on barrel length. Velocity does, but unless you're hunting coyotes at 400yds I wouldn't suggest an AR for that range or purpose. I like the 18" rifle gas length as an all-around SPR myself. You don't give up much to a 20" barrel and the rifle length gas system is just better.

 

[Chuckman]

A 14.5"/16" can be accurate at those ranges. A good optic, it will be crazy-deadly at those ranges. But if you want a 20", BCM is under $300; Faxon, $195.

 

[Climberman]

https://ballisticadvantage.com/ar15-barrels?barrel_length=34

I am seeing $200 to $250.

 

[Ikarus1]

https://www.graniteridgeoutfitters....vernment-Profile-Rifle-Barrel-BABL556026M.htm

$148 Shipped with coupon code BALL

 

[Bunsen]

White Oak has 20", 22", and 24" for under $300

https://www.whiteoakarmament.com/shop/barrels.html

Also, John at Kestone Accuracy will cut whatever length you want and thread for $20. It's a Green Mountain blank.

https://www.keystoneaccuracy.com/ar-15-service-rifle-uppers.html

 

[Climberman]

BTW, I have a bone stock 16" BPM with a 1-4x optic and have hit plates at 500 yards with @JBoyette .

 

[Gator]

Green Mountain 20", $176.95. I remember because I bought one.

http://www.gmriflebarrel.com/gm-m17-20-5-56mm-m16-a2-a-r-barrel-1-7-twist/

.

 

[CZfool68]

Want to build an AR-15 in 5.56 with a 20" barrel but they are very hard to find without coming close to the $400 mark. Should I reconsider the 20" barrel? Was hoping to play around at 4 to 500 yards.

I am no AR expert, but I had an 18" Barnes that was crazy accurate. Great range gun. 16" will work fine with a good barrel and glass. Are you shooting tiny groups or steel plates? That should dictate the barrel and scope. And don't forget a trigger upgrade.

 

[Chdamn]

Accuracy depends on harmoics and your twist to weight ratio more than anything else.

You can shoot some impressive groups with the right weight bullet out of a standard 16” barrel if you take the time to find the right load and weight.

Hell I’ve got a 12 inch with a high twist that shoots a 1/2 inch MOA with 168 grain factory round from a specific manufacture. Anything else and I’ve got a 3” moa at best.