Precision AR15 Barell options

[moagm316]

I am looking into a precision AR Build. Put simply I am looking to build a little brother to my AR10. The AR10 has an 18" Barrel. I am debating a few different barrels. I am really debating two things 18" vs 20" performance to weight ratio.

1. Rainier Arms UltraMatch™ .223 Wylde Barrel - 20 SDM $446.45
2. Rainier Arms UltraMatch™ .223 Wylde Barrel - 18 SPR $328.50
3. Rainier Arms Match™ .223 Wylde Barrel - 18 SPR $237.45

All are 1:8 twist and all weigh 2Lb. 9 Oz. Both of the Ultramatch barrels are built on Schillen blanks with their polygonal rifling. The Match barrel uses a Wilson blank. I have also been told that I can special order an 18" SDM barrel for the same price as the 20" with a weight savings of 4 ounces.

Any thoughts as this will be one of my first .223/5.56 precision builds?

 

[excess]

Re: Precision AR15 Barell options

You'll night likely see an accuracy change from barrel length alone. Velocity will be higher for the longer barrel.

How far are you likely to shoot this?

 

[Temp9]

Re: Precision AR15 Barell options

CNC is right, both barrel lengths will shoot equally accurately. What matters is what you want to do with it. Honestly, you only gain about 60fps with the extra 2 inches. I'm a huge fan of 18" AR's, so unless you really want to extend your max range, I would go with the 18".

I have a 16" Ultramatch and it shoots incredibly. Also cleans up like nothing. I've never seen any significant copper fouling in mine, and a single patch of KG-1 solvent removes 90% of the carbon fouling. Couldn't be happier with it.

FYI, the Shilen blanks are Ratchet rifled, not polygonal. Polygonal implies hammer forged, which these barrels are not.

 

[RufDog]

Re: Precision AR15 Barell options

In my experience, with factory loads you get nearly all your velocity by 17". I chrono'd a 17" barrel & a 24" side by side & saw 50fps difference. The only variable is they werent the same barrel, so there could be some deviation in that.

 

[moagm316]

Re: Precision AR15 Barell options

I was leaning toward the 18" length either way. I am looking at running a Rifle Length Adams Arms piston setup on it as well. The little bit heavier/stiffer SPR barell would be better than the SDM profile.

Is the accuracy difference between the ultramatch and the match worth the extra coin?

 

[moagm316]

Re: Precision AR15 Barell options

For the record the farthest I will probably shoot is 5-600 yards.

 

[Captain Moroni]

Re: Precision AR15 Barell options

I have the #2 barrel and its amazing, a real hammer to 800 w/77gr SMK's. I would go 18" for the range you will shoot also I would leave the piston off of a precision rifle.

 

[excess]

Re: Precision AR15 Barell options

^^^^
Yep, forget the piston conversion for what you're saying you want the rifle for. Its like putting mud bog tires on a Corvette, it's just not the right combination.

 

[KAZ]

Re: Precision AR15 Barell options

I have two of the LOTHAR WALTHER 8 twist wylde chamber polygonal rifling 20" and they are hammers with 55gr zmax and 77gr smks. They can be ordered with matching bolts. One was gunsmith built and one is in Larue Stealth upper. Regards

 

[moagm316]

Re: Precision AR15 Barell options

If I am running a suppressor I have been told that a piston setup is ideal. How much can a piston setup really effect my accuracy if the bullet has left the chamber by the time the piston system starts moving. This is what I have been told.

 

[TonyAngel]

Re: Precision AR15 Barell options

If you're running a suppressor, going the piston route may be worth it to you just to keep the trash out of your receiver. Whether it will affect accuracy is another question. I don't know the why, but I do know that I got better accuracy out of my SPRish builds going DI. Heck, if you are going to use the Adam's Arms rig, just give it a try. If you don't like it, you can always switch over to DI. For that matter, you can go DI then spend the extra money on the piston later.

The only thing that may give me pause with the piston, and it's only a thought, is that I've seen two Adam's Arms systems lock up tight because something got blown through the gas system and became lodged in the piston's chamber. I really don't know if running the suppressor will cause more of a carbon build up or something that will impede the operation of the piston rig. I really don't know. You might want to call Adam's Arms and ask.

As far as the barrel goes, in this day and age of advanced materials development and manufacturing processes, producing a barrel capable of MOA is no great feat. The pricing on barrels 2 and 3 is about in line with the plethora of good barrels that are on the market; but if you are considering no.1, at that price, I'd be calling Krieger.

As for the length, I'd go with the 18" with rifle length gas system. It's shorter dwell time, whether you go DI or piston, will provide for smoother, softer recoil impulses. Any velocity gain there might be by going with the 20" will be negligible.

 

[moagm316]

Re: Precision AR15 Barell options

Thanks. I will probably go the DI route and the switch once I purchase a suppressor. One other option that I was thinking of was something like a Noveske Switchblock. I have not heard of what that does to accuracy. It looks kinda big.

 

[TonyAngel]

Re: Precision AR15 Barell options

Sorry, I can't comment on the switchblock. I've never used one. Will this be the first AR that you've built yourself?

Which stock are you going to use?

 

[Blackrifle1]

Re: Precision AR15 Barell options

I have 2 AR15 ....one piston and one DI and they both have 16" barrels. I haven't noticed a difference in accuracy - only because I'm NOT doing any precision shooting and I'm an average shooter. I use my DI rifle when I want to shoot further distances (up to 600 yards) with the heavier bullets. I use the piston with 55gr/62gr bullets for regular shooting.

One HUGE difference- the piston gun is way EASIER to clean and keep clean. I have tendonitis in my right hand and it makes cleaning 10x easier for me. This is a tremendous benefit for me.

 

[moagm316]

Re: Precision AR15 Barell options

I will be using a POF Buffer Tube with a CTR Buttstock.

 

[TonyAngel]

Re: Precision AR15 Barell options

I tried the CTR on my first precision build and it just didn't quite do it for me. The UBR, on the other hand, did the trick.

This was an 18" rifle length gas build. The UBR balances it out nicely and offers a good surface for cheekweld.

 

[ccoker]

Re: Precision AR15 Barell options

a few other options for good shooting 18 " barrels I have used:
JP
Douglass from CLE