AR15 FAQ by me a noob...


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American_16_14_47
November 4, 2007, 03:23 PM
Hello all, 1st post here :D ,

Im building my first ar15 in a few months (Pinning an upper to a lower :rolleyes:) and i had a few questions that i couldnt find on this forum or anywhere else online...

1) What is the general accuracy difference between a 16" midlength HBAR [RRA] and a 16" M4 Barrel [Stag], assuming that both have the same optics? I believe both are made by Wilson, but have exactly zero proof for it. Both are chrome-lined.

2) What is the felt or noticable weight difference between these two barrels? Or is there any?

3) Is there really any accuracy gain in an RRA Heavy profile M4 over the standard Government light profile?

4) Is there any advantage in Stainless steel barrels over chrome-lining?

5) What is the expected accuracy gain when freefloating a barrel with a railed forearm (Midwest Industries, for example) from the standard handguards? Or is there really any?

6) Are there any dis-advantages to freefloating a barrel? Does it make the rifle more fragile?

7) Is going from an RRA standard trigger to 2-stage NM generally considered worth the $80.00? If so is it because of an accuracy difference or just a finer feeling trigger?

8) Is the gun mechanically more accurate with a 20" barrel rather than a 16"? That said, i'm not worried about ~.02" I mean a half MOA difference.

9) Is there any reason Krylon plastic fusion spraypaint wont work on ar furniture? At least that way the colors match.

Thank you all in advance for your help! I had a lot more questions than i thought.:eek:

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Slugless
November 4, 2007, 03:48 PM
Welcome to THR!

Q#8 - Are you going to use optics?

American_16_14_47
November 4, 2007, 03:59 PM
i will be using some sort of optics, considered everything from EOTechs to cheapo red dots and [if i can find one] a decently priced holographic sight [one like an aimpoint, but cheaper], but im leaning towards a bushnell scope and Hi-Riser mount [sold through RRA]. may be 3-9, 4-12, or 4-16, but will almost definately be a 40mm objective. im not sure if there isnt a better mount for the price, but it was half the price of the armalite's alostyr mount. (100 -> $50)

Bottom line? im split down the center between a scope/mount and an EOTech.:uhoh:

Slugless
November 4, 2007, 04:27 PM
Okay, then don't worry about #8. 16" or 20" is fine.

W.r.t. barrel length & weight, balance & handiness is my key here. My M4gery is a handy little carbine w/ the GI profile barrel. I don't shoot it as well as my A2-style w/ GI barrel which is not, er, unhandy for a full length. I originally bought my A2 style with an HBAR but never really liked it. I'll take off the carryhandle & put some nice optics on it, though, for target work.

That said, some of the GIs on the board recommend a sight picture with the tip of your nose on the carry handle. This is awkward with an A2 stock. I still have yet to mess around with the M4gery + sight picture. This method of consistent sight picture might be a real plus w/ the collapsible stock.

There is some accuracy difference between HBAR and GI profile if you're going to burn off lots of rounds without time for cooldown. For range/target shooting, not a big deal, the GI is just fine. Cooldown is enhanced by leaving the bolt open when your not shooting. Not a good idea in windy/sandy environs, of course.

If you get a chance, go fondle a selection of ARs to see what you like w.r.t. balance, etc. If you don't get to, then my opinion is to get the GI unless you're going to be taking "tactical" shooting courses, etc.

Kindrox
November 4, 2007, 04:30 PM
3) Not if the steel is cold, and in my opinion not a lot if the steel gets hot. HBAR is for those who actually want a heavy gun, like for a real bench rest gun, and for those who don’t have the money to shave the excess steel from the barrel.

HBAR is cheaper to produce and thus its popularity.

4) Stainless has a very slight increase in accuracy, at the cost of some barrel life.

5) The improvement will be with a free floating hand guard, but I cannot tell you how much.

7) Yes and yes. Softer trigger will of course be more enjoyable to shoot and will make your job of trigger pull easier. For most that will translate into better accuracy. This is one of the must have improvements IMHO.

Slugless
November 4, 2007, 04:50 PM
+1 on the trigger, Kindrox

I couldn't believe the improvement when I dropped in the RRA 2 stage NM. They run 4.5 - 5 lbs, which I like in an assault rifle.

My groups shrunk to 2/3 the size they were. Great value. If you can get a RRA 2 stage NM for $80, don't hesitate. They're $122 at Brownells.

RevolvingCylinder
November 4, 2007, 06:13 PM
Those are some excellent questions.

As far as production AR15 barrels go, the heavier profiles are supposed to perform better hot than the lighter barrels. I haven't noticed a huge difference myself. The heavy barrels allow for more stable shooting in the prone or off a rest. This will translate into easier to obtain accuracy. This is sacrificed in the balance of the rifle. The AR15 is already a front heavy design and the HBARs make it VERY front heavy. This can be a bit of a minus shooting free-hand. It's also harder to "swing" this way.

The 2-stage trigger is a superior trigger. It's up to you if you think it's worth $80 but I don't know many people that complain about their trigger being better. You can squeeze the same amount of accuracy without it but it takes more effort.

I don't have any experience with the free-floats and wouldn't mind being informed of the degree of improvement myself.

American_16_14_47
November 4, 2007, 08:04 PM
Thank you all a lot for your help, this has been a very enlightening few hours! :) I have decided to definitly upgrade to the two stage match trigger, and the 16" m4 profile barrel. Still interested in hearing about the freefloat handguards though :D . Also, the optics are a bit of a toss-up too. EOTech~Scope? What sized groups can people generally get with an EOTech? [Assuming it has a competent shooter] Most of my shooting will be general plinking (25-300 yds. hoping to get a big paper-plate group at the latter distance once in a while), might sneak in some coyotes too (~50-75 yds. at the most, in the woods.), and of course TEOTWAWKI and Zombie-Control.

Bartholomew Roberts
November 4, 2007, 09:05 PM
1) What is the general accuracy difference between a 16" midlength HBAR [RRA] and a 16" M4 Barrel [Stag], assuming that both have the same optics? I believe both are made by Wilson, but have exactly zero proof for it. Both are chrome-lined.

For all practical purposes there is no real difference using optics. With irons, the midlength will have a slight edge in sight radius.

2) What is the felt or noticable weight difference between these two barrels? Or is there any?

About 8oz of weight difference. It actually feels slightly heavier because all of the weight is in front of the barrel nut on a long lever, so it affects balance. Not that you can't handle an HBAR well; but you'll notice it.

3) Is there really any accuracy gain in an RRA Heavy profile M4 over the standard Government light profile?

No.

4) Is there any advantage in Stainless steel barrels over chrome-lining?

Easier to machine stainless steel so they are usually finished better compared to a chrome-lined barrel. They hit their sweet spot for accuracy sooner than a chrome-lined; but lifespan is slightly shorter as well.

5) What is the expected accuracy gain when freefloating a barrel with a railed forearm (Midwest Industries, for example) from the standard handguards? Or is there really any?

Based on my own experiences and what I've seen, freefloating a barrel is usually good for cutting down five-round groups by about 0.5" at 100yds.

6) Are there any dis-advantages to freefloating a barrel? Does it make the rifle more fragile?

With some systems, it can be harder to wipe down the external part of the barrel. It does not make the rifle more fragile. Depending on the rail, it can make the rifle heavier (in front of the barrel nut as well); but there are rails that are lighter than the standard handguards.

7) Is going from an RRA standard trigger to 2-stage NM generally considered worth the $80.00? If so is it because of an accuracy difference or just a finer feeling trigger?

Depends on what trigger you have already. The RRA is a nice, basic match trigger though if you need one.

8) Is the gun mechanically more accurate with a 20" barrel rather than a 16"? That said, i'm not worried about ~.02" I mean a half MOA difference.

No. It is a little easier to be accurate due to longer sight radius and less drop and windage due to higher initial velocity.

RevolvingCylinder
November 5, 2007, 12:02 AM
Based on my own experiences and what I've seen, freefloating a barrel is usually good for cutting down five-round groups by about 0.5" at 100yds.
Depending on the rail, it can make the rifle heavier (in front of the barrel nut as well); but there are rails that are lighter than the standard handguards.
Really? ~1/2 MOA? What free-float tubes are there out there that don't really add weight? I assumed they all weighed the rifle down(learn something new everyday) compared to the standard handguards.

Frog48
November 5, 2007, 12:58 AM
I wouldnt worry too much about accuracy. Any AR made by a reputable company will shoot more accurately than you can aim. I know that when I have bad shots, its user error, not the gun itself.

Yes, the HBAR will feel slightly heavier, but its not a deal breaker.

I have an HBAR Bushmaster carbine, and like it alot.

When I bought it, I didnt know much about AR's. All I knew was that I wanted a M4 lookalike. I didnt know what an HBAR was, as opposed to a M4 profile barrel, so I bought it without realizing it. As it turns out, I'm happy with it and have no complaints, as I have no need for that M4 cut to mount an M203 grenade launcher, and the weight difference doesnt bother me.

Bartholomew Roberts
November 5, 2007, 10:32 AM
Really? ~1/2 MOA? What free-float tubes are there out there that don't really add weight? I assumed they all weighed the rifle down(learn something new everyday) compared to the standard handguards.

The Daniel Defense (DD) First Generation Rails, the DD Lite Rails, and the PRI carbon-fiber tubes with the aluminium barrel nut all weigh less than the installed weight of standard double-heat shield handguards IIRC (I know the DD rails do). The aluminium barrel nut helps a lot with that. You just have to be a bit gentler on installation (no 3' cheater bar on the wrench backed by a hammer; but you can still be fairly aggressive) or you can oblong the holes on the aluminium barrel nut.

On the 1/2 MOA, that is what my own records show when I went from M4 handguards to Knight's Armament free-floats on my carbine. If you go over to AR15.com/AR15 and search for posts by a guy called "Molon", he has much more detailed data showing a similar change on a free-floated barrel. Unless it is tacked to the top of one of the forums (Rifles, Uppers, etc. or AR15 Discussions), you'll need to search the archives to find it which requires being a paying member.

taliv
November 5, 2007, 10:44 AM
just a comment... the combination of M4 profile and match trigger doesn't make much sense to me.

Kindrox
November 5, 2007, 11:28 AM
There are three options I paid for and would do so again:

2-stage trigger
Pencil profile barrel
Flat top receiver (the cost the bolt on carry handle, not an issue if you don't want one).

The pencil profile barrel does cost me accuracy, the rifle is so light weight it is easier to disturb the point of aim. Otherwise the gun is much more accurate than I am, hot or cold.

Yes the pencil profile gets hot quicker, but that is why I take several guns to the range. Since the point of the gun was for shft, I'll take the light weight.

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