Rock River LAR-15 question

The 1/9 twist limits you from using some of the heavier, specialist ammo. Not as much as 1/12, which pretty much limited you to 55gr projos.

The HBAR barrel has all sorts of promoters and detractors (especially over on arfcom).

Rather a lot of that is from "what kind" of HBAR one is talking about (and often assuming everyone knows your specific meaning.
The "milspec" HBAR has a relief cut in it for mounting an M203.
There are HBAR that have large diameter for their entire length.
There are even (a smaller minority) HBAR that are only large diameter to the FSB.

A full-length HBAR barrel is going to be some amount "more rigid" (even though all gun barrels have harmonic flex when firing). They will absorb more heat than thinner profiles. How much of either of those fuels no sal quantity of flame wars elsewhere. As does whether the casual shooter will ever put enough ammo through one in a short enough time as to even matter.

Things we can assert about an HBAR--it will resist the bending moment of using a shooting sling as an accuracy accessory (why it was ginned up in the first place). Also, it will make the rifle heavier. Whether you will notice that weight is a subjective question, not an objective one.

As to "1 MOA out of the box," well, almost any new-made rifle clamped in a nice rigid vise will meet that standard (as will everyone on arfcom, at least those who don't shoot 1/4MOA off hand, and have the one shot group to prove it). Wylde chambering is just smart engineering, given the enormous variety of ammo available in .223 or 5.56nato.

I have an RRA Entry Tactical that I bought in 2007. I got it with a heavy 1:9 chrome-lined barrel. It is a sub-MOA shooter. I mainly shoot .223Rem loads with 55gr pulled bullets being pushed by 25.2gr H335. I’m sure it could do even better with newly manufactured bullets.

Has nothing to do with the barrel profile or twist and little to do with the Wylde chambering. The accuracy guarantee is what RRA has come to expect from the barrels they use, Wilson Arms air-gauged. These are very good barrels dollar for dollar and no doubt perform to that claim or close enough for Rock River to make that claim.

No doubt there are plenty of poor shooters not capable, plenty of fibbers claiming every one of their rifles “shoots cloverleaf/dime size/ insert phrase here all day long if I do my part”. For my sample of 1 I’ll simply say that for 5-shot groups with a 3-9x Leupold I managed more sub-1” groups than not. Once I pulled the scope to shoot irons or a red dot I could still hit vitals but with plenty of paper between holes.

Mine liked nearly every weight I loaded from 50gr to 62gr using near max charge of Varget. These groups were close enough in size that determining a clear cut “most accurate” would have been a guess at best, perhaps less so for a better marksman. I did not venture into heavier bullets.

One thing most every target shooter, however you define the term, will agree on is that chrome lining the bore will not improve accuracy. The reason being that the application is not uniform in thickness which of course robs the barrel of some potential. Great for barrel life and longevity but not an accuracy enhancement.

Slater said:

Attended a local gun show with a shooting buddy some time ago. He was in the market for a "Plain Jane" A2-type rifle for a plinker/range gun. IIRC, a vendor had a couple of these particular RRA models on the table and he looked them over. Came back saying "barrel's not chrome-lined. That's a no-go". Think he ended up buying a Spike's. So I guess the chromed bore thing is a deal killer for some folks.

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Many people are easily manipulated into the marketing ploys of many companies, so if it does not have this or that than its no go and the sad part is that the product is just as flawless and reliable as what the individual is looking for. It can be a trend as is now with the 6.5 creed more but the truth the 6.5 caliber was being produced over 100 years ago. Than there is also the fact that if it is not mil spec it is not good. I find if funny because spending over 2 decades in the military for me mil-spec means lowest bidder wins. As "Skylerbone" indicated the accuracy is due to the expected tolerances of what RRA will accept. Many people will buy a BCM, or other top tier AR based on what the buying frenzy is and the sad part is that their skill levels will never be able to meet the capabilities of what a good firearm can achieve. With todays advancement in metallurgy every single factory rifle that you buy whether $400 or $4000 it is a MOA shooter, what is not is the shooter. I bought the RRA Predator Pursuit several years ago and back than they were guaranteed to shoot 3/4 MOA, mine shot better with factory ammo, and it is not chrome lined.

In a civilian AR, Ferritic Nitriding has kicked “Crome lined bore” to the curb...

Use a good barrel in an AR and you should expect 1moa, or slightly less, given an appropriate bullet choice and load selection, and a shooter capable of delivering with an AR.

The Wylde chamber, and facsimiles, do tend to shoot the best groups among AR’s, but getting a 223rem SAAMI spec or 5.56 spec chamber to shoot sub-moa isn’t a challenge. 1:9” twist isn’t magical, any twist will shoot small groups when given an appropriate bullet weight. External contour - aka barrel profile - has nothing to do with inherent accuracy of a bore. A good bore in a pencil barrel will outshoot a poor one in an Hbar. Stiffer barrels are harder to influence, and heavier barrels don’t heat up as quickly, and cool down more quickly, which can be an advantage in some higher rate of fire competition circumstances, but light barrels can shoot just as well as heavy barrels - certainly sub-moa.

There’s nothing I want from a chrome lined barrel in any of my AR’s.

If you want a factory offered, fixed handle, 20” Hbar which will shoot very well with 50-69grn bullets, that RRA is a good choice.

ms6852 said:

...there is also the fact that if it is not mil spec it is not good. I find if funny because spending over 2 decades in the military for me mil-spec means lowest bidder wins...

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The lowest bidder that can meet the standard. If you think that's not important, you're wrong. There are dire consequences for contractors who cannot meet the standard- and the truth is, the standard for a mil-spec AR produces a fine rifle.

...With todays advancement in metallurgy every single factory rifle that you buy whether $400 or $4000 it is a MOA shooter, what is not is the shooter...

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While many shooters cannot wring the full potential from their rifle, there are still rifles that don't offer much potential to begin with.

MistWolf said:

The lowest bidder that can meet the standard. If you think that's not important, you're wrong. There are dire consequences for contractors who cannot meet the standard- and the truth is, the standard for a mil-spec AR produces a fine rifle.


While many shooters cannot wring the full potential from their rifle, there are still rifles that don't offer much potential to begin with.

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You miss my point or better yet I failed to communicate my intention. As we were talking about the comment the op made that his friend had passed up a good firearm because the barrel was not chrome lined, my intent was that some indidividuals will pass up on a good deal not knowing that as civilians we do not need all our firearms to meet military specs also. There are quite a few firearms that we can choose from that will meet or surpass our intended use. It is true as you state that many shooters cannot wring the full potential from their rifle, there are still rifles that don't offer much potential to begin with and the reason for that also is if you read the various forums many novice shooters are always asking what is the "cheapest" gun, the cheapest rifle, the cheapest scope and so forth and as we are a capitalist nation the manufactures will supply the demand for firearms in which those tolerances are going to be more lax. But on the average you don't need to pay thousands of dollars for a custom rifle that shoots moa as inexpensive not cheap factory rifles will shoot moa if the shooter can.

Slater said:

You do hear about the 4140 vs 4150 barrel steel. Not sure what Rock River uses, but is there a lot of difference between the two?

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If you meet an an average AR fan with 1-3 AR’s and at most has burned out 0-1 barrels who tells you anything about 4150 lasting longer than 4140, then you’ve met someone you know can’t be trusted. They’ve not done anything with these rifles to have proven any significance between these alloys.

CapnMac said:

Things we can assert about an HBAR--it will resist the bending moment of using a shooting sling as an accuracy accessory (why it was ginned up in the first place). Also, it will make the rifle heavier.

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That is absolutely true. Coming off my Colt H-bar (full-length heavy) and using the sling, I put a sling on a DPMS 16" carbine. I was surprised to find my POI shifted about 5" left and down with the pressure of the sling!!! I was astounded.

Like others have said... quality in, quality out... a proper barrel sourced from a reasonable source should provide good accuracy with the proper bullet weight and construction. That's absolutely true, too... my Colt H-Bar, with it's 1:7 twist... pretty much hates anything 55grn, but serves up both 62 and 69grn bullets well.

I can tell you about my Rock River ARs. I have a 20" in 5.56 and a 26" heavy barrel in .308. Both are more accurate than any other AR I have. Couldn't tell you why. (the 5.56 is a 1:9, Wylde; the .308 has a pretty-much-standard 1:10)