Barrels...and other parts

[alamo5000]

Since I have gotten a kick start on my AR build I would like to have a discussion on my next couple of logical components.

The first of which is an AR barrel. As this is going to be a key component I would like to learn a lot more than what I already know and possibly be steered in the right direction.

I am thinking I would like a 1:7 twist because I would like the option to shoot heavier grain bullets.

It must be 16" for this go around because I don't want to have to deal with pinning a brake or doing the NFA thing...but I could be persuaded otherwise if it's not too much of a hassle. Which would mean I could get a shorter rail as well.

And for sheerly cosmetic reasons, it needs to come in black.

I know there are several types of rifling in various barrels but I don't have a comprensive list, nor do I know if they would make a huge difference in my purposes.

Now let's rewind a bit...let me say what I am going to build and how I would like it to function.

I won a CMT upper (thank you thank you thank you! :) ) and I have already ordered a billet CMT lower.

For my rail I am going to invest in a Geissele SMR MK2 15.

I have yet to even consider a muzzle device, trigger, optic, or any of that. But I am trying to keep things focused on the barrel (for now).

My aim is to have an AR (with a reasonable optic) that will be a 100 yard gun. I want the option to reach out to 200 yards, but odds are I will never go beyond that mark. I do put a premium on better accuracy... which of course is also an ammo issue.

I am pretty keen on accuracy that said I am not really talking bench rest accuracy where I would be reloading each round...I would be shooting off the shelf ammo for the most part.

I know some types of rifling would potentially perform differently than others and some might be easier to clean than others...

I hear the term 'cold hammer forged' and 'chrome lined' but what are some other options? (this is designed to educate yours truly not stir up a debate)...

I was poking around the Rainier Arms website and they have 'match series' 'mountain series' 'select series' and 'ultra match'...

Some of that type of terminology gets kind of confusing...I know the bull barrels help with harmonics... those little micro quivers that happen when you pull the trigger can send a round far off way down range...but when we are talking 200 yards is it really an issue?

Please someone lay it all out there (to the best of your ability)....

(Side note: I want my barrel to be 5.56, not just .223)

[Aragorn]

I just typed up one of the longest, most informative posts I've ever written, and lost it.

I'll try and get it up again tomorrow.

[WHSmithIV]

I just typed up one of the longest, most informative posts I've ever written, and lost it.

I'll try and get it up again tomorrow.

Aragorn, I had probably started to do so before you did then my wife had dinner ready and I took a break for dinner. Hopefully I've saved you the effort of writing it again

[WHSmithIV]

Hmm.. I'll give you the best answers I can give you from all the research I did when building the one I built. You have a higher budget than I had. I built my entire rifle the way I wanted it for $506.62 based on what I could afford. Manufacturers make their own creative terms to justify the prices they charge for various products.

Let's start with barrels. Some barrel profiles and the amount of time of the technologies used require that manufacturers charge a higher price for them based mainly on how much machining has to be done for them. Government profile, bull barrel etc. Some barrels are made to be a light as possible. So, all that extra machining to make a minimum weight yet still reliably strong barrel costs more for the machine shop - it eats up their bits and lathes faster too - more metal to be shaved off. So, let's move on from that..

Next, lets go to barrel coatings/linings. There are 4 options here. 1) a stainless steel barrel. That is exactly what it is - a stainless steel barrel. It has been cut, bored and rifled and threaded for a muzzle device. There is no coating. These are also referred to as "in the white" barrels. 2) Phosphate coated barrels - these are just that - a phosphate coating has been applied to the surfaces of the barrel. The chamber won't have it. The chamber doesn't benefit much from a coating anyway and the chamber is part of the barrel extension, not the barrel. 3) Chrome lined barrels - for this type of barrel, the bore is drilled for just a tiny bit more than the caliber bullet. Then, a lining of hard chrome is applied to the interior bore of the barrel to provide a much harder surface that wears at a slower rate than pure steel. This means that the barrel will last for a few thousand more rounds passing through it before the rifling is worn down so much as to severely reduce the accuracy of bullets due to lack of spin on the bullet as it leaves the barrel. 4) (the last option) is a melonite or nitride treatment coating to the metal. Both of these processes are for all practical purposes the same. They just vary a little in the chemical acids used to achieve the same result. The process has been around for over a century and was used in Germany originally. Due to the costs of the chemicals and, more importantly, proper disposing of the old, used chemicals, it has taken a while for manufacturers to be able to gear up to use the process to commercially produce barrels. Nitriding a barrel changes the chemical molecular makeup of the surface molecules of steel and makes it very much harder than even chrome. The process is also cheaper to do than chrome lining once a company is geared up to be able to do nitride processing. The reality is that nitride barrels are the strongest and have the longest life of any others with the exception of titanium barrels.

So, lets move on to twist rate. The twist rate is the rifling of the barrel. How many inches of travel down the barrel will be required for the bullet to be spun one rotational revolution before it leaves the barrel? That provides the bullet spin during it's travel through the air and increases its accuracy as wells as flight distance. There are charts about this and it has been tested extensively. The most common bullet you get at the local ammo supply is a 55 grain bullet weight. That works best with a 1:9 twist rate. In 9 inches of travel down the barrel, the bullet gets one full spin on it. Heavier bullets like 69 grain bullets do much better with a 1:7 twist rate. In 7 inches the bullet gets one full spin. That makes those bullets rotate just a little slower during flight and gives them better accuracy due tot he weight of the bullet. 1:8 twist barrels are a compromise for the two others and will stabilize the widest range of bullet weights. Where 1:9 is best for lighter bullets, and 1:7 is best for heavier bullets for accuracy over distance, a 1:9 doesn't stabilize a heavy bullet for longer distance accuracy enough and a 1:7 twist over spins lighter bullets to where they can even break apart over distance in the air, a 1:8 twist barrel will provide the best overall performance. For the home AR, there is no doubt that 1:8 twist is the best option. 1:7 is good too, but don't plan on shooting 300 yards with a 55 grain bullet accurately.

As a side note, a 7.62x39 barrel is most usually rifled with a 1:10 twist rate. Much heavier bullet.

Cleaning is no different for any of the barrels.

If you have questions, feel free to ask them. That's what we are all here for. To help each other.

Triggers are another issue.. You'll likely have questions there for trigger pull weights, 2 stage vs. single stage for one. First define WHAT you need the rifle to do. Then design to your needs for it. Ask any questions you have and we'll all help you.

-Will-

Edited for correcting my typing errors.

[alamo5000]

Triggers are another issue.. You'll likely have questions there for trigger pull weights, 2 stage vs. single stage for one. First define WHAT you need the rifle to do. Then design to your needs for it. Ask any questions you have and we'll all help you.

-Will-

Thank you for the response so far. It does help a lot. I might go with 1:8 on the barrel but I will read more on it as it goes and choose later.

As for triggers, darn right I am gonna have some questions specific to AR triggers... but just not right now. I don't want to muddy the water. I guess I learn better when everything is on one topic and I can compartmentalize all that stuff.

Later on look for a thread about triggers LOL

As for ammo... as I have done with other firearms that I use... I have heard the phrase/thought to' pick a round and build a rifle around that'.... but needless to say once I get things going I will find the ammo I like and try to stock it for the long term. I don't like ammo shopping when everyone else is also ammo shopping.

It's more expensive upfront to do that but it all evens out in the end... that's been my habit and I don't see why an AR would be any different.

[WHSmithIV]

Just continue with this thread you started for all questions you have. IT will be easier rather than using new treads for everything. You have to compartmentalize when understanding how you want to build an AR. To build one from scratch you MUST have a bench vice or have one available to use and there are some tools you'll need. They don't cost a fortune. Use a different railed handguard that costs a little less than that Geissele one and you'll have the tools you need too. The Geissele handguards are really pricey but they aren't functionally any better than a Troy or Midwest Industries handguard or those available from several other high quality companies.

There is a pretty simple list of tools you're going to need to build an AR from scratch. The tools will cost you around $100. A few roll pin punches, a small ball peen hammer, upper and lower vice blocks (only the upper vice block is really needed), 4" vice grips, a roll of electrical tape, a barrel nut wrench, 'maybe' a torque wrench (most likely just a piece of pipe to fit over the barrel nut wrench for a little extra leverage - depends on the free float barrel hand guard) ... a castle nut wrench (if you use a barrel nut wrench and not a combo armorers wrench), a small screwdriver (if you are going to stake the castle nut for the buffer tube), a larger screw driver for the pistol grip screw and a simple couple allen wrenches or allen wrench set to have the small allen wrenches you'll need for any set screws. Do get yourself some 0000 steel wool also. That's the tools list.

[WHSmithIV]

You'll want a dab of moly grease (any automotive bearing grease will be just fine and all you need is a little dab of it) for installing the barrel and you can use a drop of blue loctite for the castle nut instead of staking the one thread.

After re-reading your original post, it really isn't going to matter which twist rate you use for a barrel. Even a 1:9 twist barrel is going to be accurate with up to around 69 grain bullets for 200 yards and most off the shelf ammo that's reasonable prices is going to be 55 grain bullet ammo anyway. I wouldn't want to take down a deer witha 55 grain bullet at 200 yards, but I live way out in the mountains. I prefer 69 grain bullet weights in my rifle for having to shoot wolves that try to attack our livestock but I still use my Lee Enfield .303 for hunting. I'm building a 7.62x39 AR to deal with predators.

What you REALLY need to do first is decide WHAT you need your AR to do. What do you want it for and what do you intend to use if for. Then, design it to your needs and desires. If you want visuals of how it will look in 3D, play around with Gunstruction - you can use it on your computer for free and just load the Unity Flash player for your browser to power it. You can design hundreds of thousands of different configurations to visualize and it's really easy to do.

Determine what you want and need first, then design to that. It's the only way to go when designing your custom rifle. You've won the upper receiver, you've ordered the lower receiver. Now you have your start. Where you go from there, the sky is really the limit.

[UWone77]

It's late, so I admit I skimmed the OP. What is your intended purpose of this rifle? HD, Weekend plinking, Training, ect? That will determine a lot of your responses.

As for Rainier's Site on barrels, here's a quick run down:

Select Barrels = Entry level match grade barrel, still has a 5.56 chamber.
Match Barrels = Mid Range match barrel. Uses .223 Wylde chamber
UltraMatch Barrels = Top of the line barrel using Shilen Blanks.

All are guaranteed to shoot sub-MOA with match ammo, well that's if the shooter does his part. Rainier likes to ask if you want to shoot quarters, nickels or dimes when asked about their match barrels.

The Mountain Series Barrels are hard use, military grade barrels. Cold Hammer Forged FN barrels with double chrome lining. I've been able to shoot 1.5 MOA groups with them. Not as accurate, but more accurate than most people including me.

[Txfilmmaker]

It's late, so I admit I skimmed the OP. What is your intended purpose of this rifle? HD, Weekend plinking, Training, ect? That will determine a lot of your responses.

As for Rainier's Site on barrels, here's a quick run down:

Select Barrels = Entry level match grade barrel, still has a 5.56 chamber.
Match Barrels = Mid Range match barrel. Uses .223 Wylde chamber
UltraMatch Barrels = Top of the line barrel using Shilen Blanks.

All are guaranteed to shoot sub-MOA with match ammo, well that's if the shooter does his part. Rainier likes to ask if you want to shoot quarters, nickels or dimes when asked about their match barrels.

The Mountain Series Barrels are hard use, military grade barrels. Cold Hammer Forged FN barrels with double chrome lining. I've been able to shoot 1.5 MOA groups with them. Not as accurate, but more accurate than most people including me.

Looks like Rainier is one of the better choices.

[alamo5000]

It's late, so I admit I skimmed the OP. What is your intended purpose of this rifle? HD, Weekend plinking, Training, ect? That will determine a lot of your responses.

As for Rainier's Site on barrels, here's a quick run down:

Select Barrels = Entry level match grade barrel, still has a 5.56 chamber.
Match Barrels = Mid Range match barrel. Uses .223 Wylde chamber
UltraMatch Barrels = Top of the line barrel using Shilen Blanks.

All are guaranteed to shoot sub-MOA with match ammo, well that's if the shooter does his part. Rainier likes to ask if you want to shoot quarters, nickels or dimes when asked about their match barrels.

The Mountain Series Barrels are hard use, military grade barrels. Cold Hammer Forged FN barrels with double chrome lining. I've been able to shoot 1.5 MOA groups with them. Not as accurate, but more accurate than most people including me.

My "purpose" more than anything is to simply enjoy shooting sports. I am not a cop. I am not a soldier (I was unable to enlist due to a serious injury)... I live in the country and we all get together and shoot for fun. I am a far cry from some top secret operator, but more like a skeet shooter who wants to expand my horizons. That said I personally try to take my own shooting beyond the whole plinking of tin cans off the fence. I like hunting just as much as the next guy but the AR won't be for hunting. I have been invited more than once to be on shooting teams (amateur) so at some point I might give 3 gun a try.

Part of the reason why I haven't jumped into AR's before now is because it never really had that 'definition'. all in all it will be for fun. I do live in the country though so there is a chance for varmint/coyote/pig shooting etc, although later I might go for an AR10 for the pig thing.

The part that I enjoy about shooting isn't just making a bunch of racket and being satisfied hitting a frisbee. I like the science behind it. It wouldn't be outside of the realm of possibility for me to give in and run a 3 gun course. Who knows until I try.

And of course there is always the prospect of home defense. But for sheer enjoyment it would probably be an 'accurate' plinker. But, I would probably keep all the rest of that stuff in mind.

On average (seeing how I can walk out into the back yard and shoot) I might go through anywhere between a magazine or two per week. If we have an event (IE BBQ/Skeet shoot/fun time out) I might go through 10 mags in an afternoon...

Don't make the assumption that I am some hotshot gunner... I am just doing this stuff for fun...That said every once in a while we do have some of the local cops out to the house and they shoot with us...just for fun...

[Former11B]

I think a Rainier Select Match medium contour (Medcon) barrel would be right up your alley. Not too expensive but superbly accurate given the shooter and the ammo work together. I run a 16" Select Match (not the MedCon...they are a hair lighter than the regular profile Select barrels I don't see on Rainier's site anymore) and get GREAT results with all weights of my handloaded ammo. I need to scrounge up some grouping targets. I even shot solid 1 MOA groups with PMC XTAC 62gr green tip.

For your purposes I don't think the performance increase and the extra $130 for an Ultra Match is going to be worth it for you

http://www.rainierarms.com/?page=sho...roduct_id=3279

My "purpose" more than anything is to simply enjoy shooting sports. I am not a cop. I am not a soldier (I was unable to enlist due to a serious injury)... I live in the country and we all get together and shoot for fun. I am a far cry from some top secret operator, but more like a skeet shooter who wants to expand my horizons. That said I personally try to take my own shooting beyond the whole plinking of tin cans off the fence. I like hunting just as much as the next guy but the AR won't be for hunting. I have been invited more than once to be on shooting teams (amateur) so at some point I might give 3 gun a try.

Part of the reason why I haven't jumped into AR's before now is because it never really had that 'definition'. all in all it will be for fun. I do live in the country though so there is a chance for varmint/coyote/pig shooting etc, although later I might go for an AR10 for the pig thing.

The part that I enjoy about shooting isn't just making a bunch of racket and being satisfied hitting a frisbee. I like the science behind it. It wouldn't be outside of the realm of possibility for me to give in and run a 3 gun course. Who knows until I try.

And of course there is always the prospect of home defense. But for sheer enjoyment it would probably be an 'accurate' plinker. But, I would probably keep all the rest of that stuff in mind.

On average (seeing how I can walk out into the back yard and shoot) I might go through anywhere between a magazine or two per week. If we have an event (IE BBQ/Skeet shoot/fun time out) I might go through 10 mags in an afternoon...

Don't make the assumption that I am some hotshot gunner... I am just doing this stuff for fun...That said every once in a while we do have some of the local cops out to the house and they shoot with us...just for fun...

[alamo5000]

I think a Rainier Select Match medium contour (Medcon) barrel would be right up your alley. Not too expensive but superbly accurate given the shooter and the ammo work together. I run a 16" Select Match (not the MedCon...they are a hair lighter than the regular profile Select barrels I don't see on Rainier's site anymore) and get GREAT results with all weights of my handloaded ammo.

This is in fact so far on my short list of barrels that I have been looking at. As I stated before (and if you can't tell) I over think a whole lot of stuff. :)

I see the prices on there but how am I going to know if I am getting screwed price wise? How will I know (other than sheer name brand) know that I am getting something in spec that will work? I think sticking to major manufacturers in my case is a good deal... I don't mind springing an extra $50 if it means I truly gain something by doing that. On the other hand I am not paying merely for a 'name'.

Another question I have is barrel contours. I have no idea why they have different contours and if this effects anything. I know some are dimpled, or are fluted to help cool the barrels (more surface area) but for me, I don't think that will make a huge difference for me. Hopefully i don't end up in some fire fight.

Not trying to sound like an ass, but if I build a decent rifle and I shoot the barrel out 2 years later... I can buy another barrel. It's just like a car. Eventually the windshield wipers wear out. That's routine stuff as far as I am concerned.

All that said, the overwhelming amount of choices simply scare me away from getting into this stuff. A barrel seems simple, but then again apparently it's not :)

And don't even get me started on triggers (yet). I want to discuss them too but for now I am staying right on task with the barrel thing until I can flesh that out and be relatively confident that I am not getting screwed over price wise or on something that's not what is right for me.

[Former11B]

First off, there is nothing wrong with doing the research and asking a lot of questions. You will be less likely to regret a purchase and be happier overall with the rifle you've built EXACTLY to your standards, and if you do need to re-evaluate a part after you get it and use it, then you'll have a better idea of which direction to go. Also, you'll be better equipped mentally for future builds based on your requirements and also be able to help future AR beginners, whether they are forum members or friends/family.

As far as barrels go, the MEDCON (not to sound stupid) is a happy medium between light/pencil barrels and heavy/HBAR profile barrels. Heavier barrels are more rigid and heat up more slowly during higher rates of fire. In terms of rigidity, think of hanging a suppressor on the end of a light vs heavy barrel. You'll likely get more "sag" with the pencil barrel and see a greater effect on POI shift than the heavier barrel. The MEDCON is a compromise.

With fluting/dimpling, it's a way to shave off weight while increasing surface area for cooling while retaining rigidity. As far as dimpling goes, you'll probably pay a premium for it, and if you are getting the rifle down and dirty and are a really picky about cleaning...you'll be going to town on that thing with a toothbrush lol

Don't let the amount of choices scare you. Just look for what meets your needs and your budget, but don't forget: unless it's on sale, you usually get what you pay for in this industry. I am a firm believer in "buy once, cry once" in the firearms world...also, the respected names out there will take care of you in the unlikely chance something is wrong with their product. I'd rather buy the $250 Rainier barrel once then try to skimp out on a $90 bargain basement model...and end up buying the Rainier barrel a couple months later. I also look at it like my ARs, despite being "match"/precision setups or hunting rifles may also be tasked to defend my life at some point. That's not the time I want to wonder if my gear is going to hold out (not that it applies to this conversation...just food for thought).

Also, it may be hard to find a barrel that meets all your criteria from the previous post AND it be a 1:8 twist. I don't know if I've seen a 1:8 barrel that wasn't stainless steel.

This is in fact so far on my short list of barrels that I have been looking at. As I stated before (and if you can't tell) I over think a whole lot of stuff. :)

I see the prices on there but how am I going to know if I am getting screwed price wise? How will I know (other than sheer name brand) know that I am getting something in spec that will work? I think sticking to major manufacturers in my case is a good deal... I don't mind springing an extra $50 if it means I truly gain something by doing that. On the other hand I am not paying merely for a 'name'.

Another question I have is barrel contours. I have no idea why they have different contours and if this effects anything. I know some are dimpled, or are fluted to help cool the barrels (more surface area) but for me, I don't think that will make a huge difference for me. Hopefully i don't end up in some fire fight.

Not trying to sound like an ass, but if I build a decent rifle and I shoot the barrel out 2 years later... I can buy another barrel. It's just like a car. Eventually the windshield wipers wear out. That's routine stuff as far as I am concerned.

All that said, the overwhelming amount of choices simply scare me away from getting into this stuff. A barrel seems simple, but then again apparently it's not :)

And don't even get me started on triggers (yet). I want to discuss them too but for now I am staying right on task with the barrel thing until I can flesh that out and be relatively confident that I am not getting screwed over price wise or on something that's not what is right for me.

[mustangfreek]

My 18" rainier match barrel consttantly shoots under a moa with my handloads. I also have a new mega barrel sittin here i need to get out and shoot. It is suppose to have the same accuracy guarantee as the rainier barrels

[Tyrannosaur]

So the write up on barrels above was very informative. I have been saving for a new barrel and was pretty set in the Centurion arms 16" barrel. Then I saw and read about the new Mega arms SS nitride coated barrel. My question is which one in your opinions would be the better option, price aside. I know both will serve me well and I'll most likely die before I come close to shooting it out. Thank you in advance.