I have an entry level AR in the form of a Ruger AR556. I have $600 to put into it. Presently, I have the rifle as it came in the box.

Should I use the $600 to upgrade the Ruger or sell the Ruger and buy something off the shelf that will shoot 1MOA or less?

I think you're better off building, if sub MOA is your goal.

Don't sell the Ruger.  Buy parts as you can and build a second rifle.

It is a buyer's market, you'll lose big time on that Ruger. You can buy them new around $400 so expect less for yours as used. 

I would build new or look into a new barrel and trigger for your Ruger. You could do that for under 600

Also need to consider the ammo you're shooting. 

start with building a new upper

add a lower when more funds are available

A LaRue barrel/upper and good (match grade) ammo.

Done.

This.  Larue trigger when they're on sale for $99, Larue or other quality barrel for around $200, upper receiver $50.  Rail and BCG of your choice.  Now is the time to buy.

Free float the barrel. Get a good 2 stage trigger, or light pull single stage. A decent scope. Then find ammo that shoots best with your barrel's harmonics.

You won't shoot sub MOA without pricey ammo.

I have builds that are capable of sub MOA.  In theory.  Lol.

If you already have a free-floated rail: Spend all $600 on a match barrel and have it installed. Bam, you now have a sub-MOA gun.

Of course now you'll want a nice optic, a good trigger, reloading setup, different buttstock to work with beanbags, a brake, etc, etc. Pretty much enough for a completely new gun. See why we call this a disease instead of a hobby?

I didnt use to think so either, but I recently shot a .8" 5 shot group at 100 yards thru a $99 PSA stainless barrel using .36 Hornady 55 gr steel match ammo.

I would get something with a nitride or stainless barrel.

Im sure its been said but the main things are quality barrel, quality trigger and quality ammo.  yes, there is more to it, but those 3 are the main factors.

If you have the tools, or access to the tools (like at an LGS, mine charges $15 to rebarrel) required to rebarrel, then that is the cheapest fastest option.  Rebarrel with a Lothar Walther for $250, free float with an ALG EMR for $100, put in a nice match trigger like the velocity AR for $150, spend the rest on ammo and optic and bipod and rear bag.


If you don't have the tools, the buy the tools and build a new upper with the same parts just skip the trigger for now.

Why do you say that? Neither of those things has any relation with accuracy.

I will also add, good glass is a must.  You don't need to go drop 1k+, but get something around 300 and u should be ok.

From one owner to another I would start with a trigger upgrade and a decent optic. See where that gets you using some quality ammo. If you're still not satisfied then upgrade the barrel. Most rifles can out shoot their owners so make sure you focus on the fundamentals of shooting.

Well, I'm going to take it with me to Colorado. Even bought some CO approved 15 round mags and see what I like or don't like about the rifle.

I am thinking the Larue barrel seems like a winner. I have seen POF Puritan 5r in Wylde chamber but not much in the way of reviews

I think if I get the Larue I can get their trigger for $99 which seems like a steal.  

I have all the tools to do this but what about head spacing? People seem to say it isn't an issue with AR's but is that really true?

There are a ton of Free float options for less than. $200 so that shouldn't be hard to find something nice.

Ballistic advantage stainless barrel with an ALG handguard and an SSA-E trigger.

Just when I start to think I have everything nailed down you have to muddy the waters
That ballistic advantage barrel has some great reviews. The ALG handguards are going to the top of the list. If I find the SSA-E at a good price I will jump on it. I've had 2 so it's a known quantity.

The answer is three words:  barrel, barrel and barrel.

It pretty much begins and ends there.  Yes, you need to free float it.  Yes you need a lighter, smoother trigger, but the defining characteristic will be a match grade stainless barrel, 1:8 twist with a Wylde chamber.  And unless you use match grade ammo, you'll not attain repeatable sub MOA consistency.

Keep your Ruger and make these upgrades.

Compared to a chrome lined barrel, each can attain superior accuracy.  Chrome lining is mil spec and has durability benefits.  But, it is a plating applied over the top of the lands and grooves of the barrel rifling.  It can vary in uniformity and degrade accuracy.  Nitride does not alter the surface dimensionally.  It hardens the steel at the molecular level leaving the bore otherwise the same.

Most match grade barrels are stainless, usually 416 or 410.  Most custom barrel makers prefer 416, as it machines better and provides a more precise finished product with less variation in straightness and bore dimensions, typically within .0002" all the way from muzzle to chamber, and can be hand lapped with better control.  This holds true whether using single cut  rifling or pull button rifling, the two techniques used for sub MOA custom match barrels.

Some match stainless barrels, especially for national benchrest competition, are being nitrided to harden them to extend barrel life without altering the rifling and bore or chamber dimension.  Best of both worlds where appropriate.  You will never see a chrome lined barrel in the top finishers at national benchrest or other precision shooting unless class rules require it.

A better question would be why not employ nitride surface hardening rather than chrome lining where accuracy is the goal with an ordinance steel barrel?  And why not begin with 416 stainless if match grade sub MOA accuracy is required?