PDA

View Full Version : Precision AR 16" barrel?


addyyoon
02-23-2011, 9:38 AM
Hey guys,
I was looking into building a precision AR upper and I was wondering what difference would I get with a 16" SS bull barrel witha 1:9 twist compared to a 20" SS bull barrel with a 1:7 or 1:8? Also, what's the heaviest bullet I can shoot out of a 1:9 twist barrel? Is it that difficult to assemble an upper receiver (barrel, gas block, gas tube, NOT the forward assist, BCG)? Do I need to check headspace and stuff like that? I know it's a pretty big question, but I know this is the place to ask haha. Let's here it!

killshot44
02-23-2011, 11:12 AM
Figure ~50fps per inch of barrel difference...a 16" is not optimum for precision/long range.
Most 1/9s will do well with 69gr, some can throw 75s but not many.
Get a barrel with a matched bolt, no headpacing to think about.
Assembling an Upper from parts is not too difficult with the correct tools.
If it's a target gun, hard to do better than a WOA 24/26" 8Twist Wylde.

DDRH
02-23-2011, 11:16 AM
a Recce build?

RRichie09
02-23-2011, 11:27 AM
Hey guys,
I was looking into building a precision AR upper and I was wondering what difference would I get with a 16" SS bull barrel witha 1:9 twist compared to a 20" SS bull barrel with a 1:7 or 1:8? Also, what's the heaviest bullet I can shoot out of a 1:9 twist barrel? Is it that difficult to assemble an upper receiver (barrel, gas block, gas tube, NOT the forward assist, BCG)? Do I need to check headspace and stuff like that? I know it's a pretty big question, but I know this is the place to ask haha. Let's here it!

What distances are you shooting?

Will the rifle only be used at a range?

From 6mmbr.com
1:12" 65gr FB
1:9" 73gr BT
1:8" 80gr BT
1:7" 90gr BT VLD

Upper is easy to assemble with the right tools. You can't get by with make shift tools like a lower.

Checking headspace isn't really a concern but I would just to be safe.



Have you looked at this barrel?
http://www.rainierarms.com/?page=shop/detail&product_id=809

DDRH
02-23-2011, 11:36 AM
What distances are you shooting?

Will the rifle only be used at a range?

From 6mmbr.com
1:12" 65gr FB
1:9" 73gr BT
1:8" 80gr BT
1:7" 90gr BT VLD

Upper is easy to assemble with the right tools. You can't get by with make shift tools like a lower.

Checking headspace isn't really a concern but I would just to be safe.



Have you looked at this barrel?
http://www.rainierarms.com/?page=shop/detail&product_id=809

good info, but i think 80gr and heavier, u may need a chamber with extended lead?

can anyone chime in and confirm? thanks!

i'd recommend at least 1/8.

addyyoon
02-23-2011, 11:36 AM
Thanks guys for all the info. I'm trying to get a decent build for something I can shoot at the range and also hunt with. I was looking at JSE Surplus and their custom builds which seem decently priced, but I think you can only get them with 9twist and no threading for a brake. Building the upper appealed to me because I'd be able to buy things piece by piece in order to not break the bank. Any suggestions? Everything above's been really useful, thanks again!

Nathan Krynn
02-23-2011, 11:43 AM
18" WYDLE chanber, rifle gas.

The Wydle chamber is perfect for the 80gr bullets but they do not fit in a magazine so its a trade off, they are designed for 1k yard competition.

Honestly though it seems you are trying to get a jack of all trades AR but remember that a jack of all trades is a master of none.

RRichie09
02-23-2011, 11:44 AM
Thanks guys for all the info. I'm trying to get a decent build for something I can shoot at the range and also hunt with. I was looking at JSE Surplus and their custom builds which seem decently priced, but I think you can only get them with 9twist and no threading for a brake. Building the upper appealed to me because I'd be able to buy things piece by piece in order to not break the bank. Any suggestions? Everything above's been really useful, thanks again!

Buying it piece by piece will assure you that you will go over budget. Plus if you don't plan on buying more ar's in the furture the price of the tools needed to build the upper will negate any savings.

I built my upper, but mostly to learn about the gun and I love building sh*t.

6mmintl
02-23-2011, 11:50 AM
Go with a 20 " free float tube forend, flat top, picatinny front gas block, 1x8" twist and dont look back, you can shoot up to 82 grain SMK for long range and 70 SPFB for hunting with decent velocity. Get a brake and harris bipod if your varmint hunting.

As far as 80 grain bullet throat lead I believe you will be ok as most chambers are pretty generous unless you spec in a custom match reamer (wilde/target/etc.)

Download any 52/55/60 grain bullets to about 2800/2900 FPS and youll be good for short range 100-300 yard accuracy.

addyyoon
02-23-2011, 11:57 AM
Opinions on this?

Stag-15 Model 6H Varmit
$560.00
Caliber....5.56 Nato Chamber
Upper......A4 Forged and Mil Spec.
Sights.....None/Gas Block
Barrel.....24" Stainless Steel 1/8 Twist

RRichie09
02-23-2011, 12:00 PM
The nato chamber is looser than a wylde chammber and thus will affect accuracy if you are looking for a high level of precision. Maybe someone with more first hand experience can tell you what kind of loss of accuracy you are looking at.

You could also go with a .223 chamber but that is not the normal and you can NOT shoot 5.56 rounds out of it.

addyyoon
02-23-2011, 12:07 PM
Haha, I'm not looking into sub-MOA or anything. Something that can hit a steel plate 100-300 yds out or the vitals on what ever I'm hunting :)

RRichie09
02-23-2011, 12:11 PM
You don't need a precision rifle to hit steel plates out to 300 yards. I can do it with iron sights out of my 16" chrome lined barrel shooting xm193 haha.

I don't know a thing about hunting though.

Nathan Krynn
02-23-2011, 12:17 PM
You are getting 50 different answers as everyone has opinions.

As the AR-15 can be configured any way you want it lends itself to be a rifle that is customized for a specific purpose. Like when a customer comes in I ask what do you want the rifle to do? Then build accordingly. If you want a hunting gun then it will not really be suited for carbine classes and "fun" gun. Typically fun guns run heavy or are very basic and not suited for hunting where it is either one of two things a heavy beast for blinds or a light gun to carry a long way.

Sounds like this is your first AR, get a basic one and lean what you want different.

What the guy said is true it will cost so much in tools that your cost will well exceed buying a complete upper.

Also I would not shoot 80gr out of a 5.56 chamber personally.

addyyoon
02-23-2011, 12:29 PM
Thanks Nathan. I put together my AR's lower and shoot through a custom built carbine upper from JSE Surplus, which is why I was looking to get another through them. Haven't had any problems with the carbine upper so I wanted to try out the longer ranged stuff with the AR

CHS
02-23-2011, 12:30 PM
Hey guys,
I was looking into building a precision AR upper and I was wondering what difference would I get with a 16" SS bull barrel witha 1:9 twist compared to a 20" SS bull barrel with a 1:7 or 1:8? Also, what's the heaviest bullet I can shoot out of a 1:9 twist barrel? Is it that difficult to assemble an upper receiver (barrel, gas block, gas tube, NOT the forward assist, BCG)? Do I need to check headspace and stuff like that? I know it's a pretty big question, but I know this is the place to ask haha. Let's here it!

What you are looking for here ^^^

Is totally different than what you are looking for here:
Haha, I'm not looking into sub-MOA or anything. Something that can hit a steel plate 100-300 yds out or the vitals on what ever I'm hunting :)

addyyoon
02-23-2011, 12:36 PM
I suppose you're right bdsmchs. Ok let's rephrase. Precision AR that won't break the bank of a poor college kid trying to get hist start in long range shooting. Something that can also double as a varmint or deer (possibly) gun. :D

RRichie09
02-23-2011, 12:50 PM
I suppose you're right bdsmchs. Ok let's rephrase. Precision AR that won't break the bank of a poor college kid trying to get hist start in long range shooting. Something that can also double as a varmint or deer (possibly) gun. :D

I don't think you mean precision if you are shooting steel at 300 yards. Also, what ranges are you looking at when hunting varmint?


Did you just say deer? Oh no! :hide:

CHS
02-23-2011, 12:54 PM
I suppose you're right bdsmchs. Ok let's rephrase. Precision AR that won't break the bank of a poor college kid trying to get hist start in long range shooting. Something that can also double as a varmint or deer (possibly) gun. :D

Almost any quality factory upper with a factory trigger is going to be capable of 1.5-2MOA with ease.

If you want something that you can practice precision shooting with, you'll need a quality FIXED stock so that you can practice your cheek weld.

Just build yourself a decent gun using quality name-brand parts and practice. Once you know a little more about what you REALLY want, get a bolt-action :)

Nathan Krynn
02-23-2011, 1:31 PM
Agreed, except the bolt gun part.


I'd say get more ammo and practice with what you have.

Dear god don't start hunting with a .223 cal unless you have been hunting all your life, a lot of places it is illegal too.

If you are shooting for groups a 1/9 16" is not the barrel for you. You want more velocity which means a longer barrel to take advantage of those higher BC bullets.

A 1/9 19" is for 55gr plinking really.

DizzyD
02-23-2011, 1:32 PM
Look into the RRA 20" SS 1/8 twist Predator Pursuit complete upper

addyyoon
02-23-2011, 1:34 PM
Haha yea, I was hoping to kill two birds with one stone (semi-auto long gun for fun and hunting). I'm also looking into a Savage Model 10 in the future, but not anytime soon. .223 for coyotes? All this stuff is really helpful guys

Nathan Krynn
02-23-2011, 1:53 PM
.223 is very good with yotes, prairie dogs, ground hogs, large rabbits, coons, armadillo's, and a few other game animals in between small and med sized like the above.

My first job was killing ground hogs in the potato patch when I was 6 ( using a 25-20 look that one up for a laugh), then armadillo on golf courses here in FL when I was 8 . I was then trained to use weapons later in life. I hunt all the time still. I am in my 30's now and I do not use .223 for hog-deer sized game, not that I couldn't get a good shot placement. But why would I want to possibly not humanely kill another life if the shot is not the best and hunting is all about not the best circumstances.

6.8 = different story for me.