AR question


PDA






phorvick
May 16, 2006, 10:50 AM
I am totally new to the AR world...hope to get my first one "soon". There seem to be an infiniate variety of possible configurations, but I have narrowed some choices down and now have a question about barrels.

Some manuf. have models with whatever is their regular barrel and then they have some with the "heavy barrel".

What plusses/minuses exist in the difference? Is it more then weight distribution? Is there a reliability or longevity component here in this choice? Heat issues? Acuracy potential?

Any reason to NOT consider Armalite, Bushmaster or DPMS ?

If you enjoyed reading about "AR question" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
Don't Tread On Me
May 16, 2006, 12:53 PM
Well, there are a number of barrel profiles.


1] Standard profile.

(aka "pencil", "superlight")

This is a .625 diameter barrel, it was what the M16 originally had. It is light, does the job. Today, you can get this type of barrel from either Colt or Bushmaster (actually a little thinner), and a couple of other places in 16" length.

2] M16A2

(aka "government")

This is the 20" barrel profile of the M16A2. It is rare as the commerical market doesn't make many of these. These are thin under the handguards, then .750 from the FSB on out.

3] M4

These are 16" barrels (assuming commerically made), thin under the handguards, then .750 outside the handguards. Has a cut out for grenade launcher attachment.

4] HBARs

These come in many different lengths. They are all .750 from the front sight base to muzzle, but they vary in thickness under the handguards. 99.9% of them are much thicker than .750 under the handguards, which makes the barrel heavy and the rifle muzzle heavy. These are purely a commerical concoction that exist solely to save manufacturers the cost of having to turn down a barrel to a smaller diameter. Less lathe time, less tooling, less waste. They are so popular, that most people have considered these to be the "norm"..and thus why other barrels listed above have nicknames like "pencil" or "superlight".

5] Bull barrels.

These are usually your 1" thick diameter barrels that people use on precision rifles. They want the thickness for stiffness. Often, these are scoped rifles with bipods meant for bench shooting or precision work.




There are a few commerical hybrids, and a couple military variations I didn't mention, but those are the main ones.


My recommendation. Go with the standard "pencil" barrel. There's absolutely no need whatsoever for the extra weight of a stupid HBAR barrel. You will hear every single justification for HBAR's, like:

1] They are more accurate. - this is false.
2] They resist heat better - this is false.
3] They balance better - this is opinion, and I'd say a really poor one.
4] HBAR's are ok, after all, you're a wimp if you complain about their weight.
5] Be a man, and carry the extra 1lb.
6] Makes the AR "feel like a real rifle"


Hbars are not more accurate, they take longer to heat, but they also take longer to cool - their resistance is the same, about the only thing they are good for is absorbing more recoil, but on a .223....yeah, exactly.

Most people need to justify the HBARs because they already bought one. I owned one and sold it. Once you go standard, you won't go back. Save yourself the trial and error, and go with the winner from the start. The standard barrel will do absolutely anything the Hbar will do, and do it with less weight. There's a reason Stoner invented the rifle with a .625 barrel.....


HTH

JNewell
May 16, 2006, 03:00 PM
Basically agree with the prior post, but want to point out that the weight difference between the A1 profile ("pencil") and real A2/M4 (skinny under the HG, heavy forward of that) is not all that great. I would avoid HBAR profiles of any length like the plague, though.

I'd also avoid 14.5" M4 profiles with a permanently attached brake. The brakes generate really significant muzzle blast and since the performance of the 5.56 bullet depends on velocity you are usually better off keeping the full 16" of barrel rather than having the last 1.5" as brake.

Thin Black Line
May 16, 2006, 03:30 PM
Whatever you get, spend the extra $30 on chrome.

Don't Tread On Me
May 16, 2006, 05:24 PM
Oh yes. 1000% agreed. GET CHROME LINED.


*Note, some manufacturers like to say "chrome moly" in order to sucker people into thinking it is Chrome lined. They are NOT.


Must say Chrome lined chamber/bore.


Bushmaster/Colt is an excellent start.

Harry Tuttle
May 16, 2006, 05:35 PM
heavy barrel / HBAR is a code word for:
Spent less time on the lathe, but has the same price

HBARs are needed in FA M-16s to combat destructive barrel heat

get a Bushmaster

i like A2s cause you can't loose the sights

some folkes like the flattops for scoped DMR duty

JNewell
May 16, 2006, 07:51 PM
Chrome - yes yes yes.

Upper - I have A1, A2 and flattop. I actually prefer A1 with a forward mount for a 1x optic like an Aimpoint. The A1 sight is basically foolproof (but you want the square A2 front sight post). YMMV on that, though.

Zak Smith
May 16, 2006, 08:36 PM
+1 heavy barrel not required.

A good start for a new AR-15 shooter is a 16" Mid-length from someone like Rock River, Stag Arms, etc.


I disagree on chrome. It is not required.

-z

Dacoda
May 16, 2006, 08:56 PM
I'll be posting some info that I learned today... everyone probably already knows this, but there may be a few lost souls like myself (until today). it'll be in the Colt AR-15 thread.

Schleprok62
May 16, 2006, 09:03 PM
I'm no expert, and these guys definitely know their stuff... However.... the chrome lining isn't "necessary" :scrutiny: and I have read that the chromemoly barrels, if taken care of, will work just as well as the chrome lined. I recently bought my first AR, and I love it... it's a great little weapon.

I personally went with the Olympic Arms (http://www.olyarms.com/?rootView=browse&view=dtl&ids=PP) Plinker Plus model with the 16" barrel. I can't say it's the best one out there, but it is the best bang for the buck!! :neener:

for about $600... you're in...

Freddymac
May 16, 2006, 09:15 PM
I might be mistaken on this, but the chrome lining was origionaly used to battle the corrosive military primers of the Nam era.

amusthj
May 16, 2006, 09:29 PM
Daniel Lija on barrel diameter;

"While there are a number of factors that determine the accuracy of a rifle barrel, one of the more critical elements is its stiffness or rigidity. Obviously the larger in diameter a barrel is, the stiffer it will be."

http://www.riflebarrels.com/articles/barrel_making/rigidity_benchrest_rifles.htm

Harry Tuttle
May 16, 2006, 10:28 PM
ar15s are not typically deployed in the same manner as bolt action paper punches

blackhawk2000
May 16, 2006, 11:51 PM
Get a 16" mid length, flat top, pencil barrel. Very good starter AR.


ETA: go chrome or go home.

amusthj
May 17, 2006, 06:19 AM
Barrel diameter is a mathematical function of barrel stiffness, and it cannot be denied that a stiffer barrel will shoot more accurately than a limp barrel, all other factors being equal. The Hbar's larger diameter offers an accuracy advantage over the standard or M4 diameter barrel style.

Consider a 16" fluted Hbar as it is a great combination between an accurate heavy barrel and a light "pencil" barrel.

Check out Bushmaster's barrel weight chart here;

http://www.bushmaster.com/faqnew/content_by_cat.asp?contentid=205&catid=103

Lebben-B
May 17, 2006, 06:56 AM
Chrome-lining a barrel makes clean up a little easier and adds logevity to the barrel. Unlined barrels are more accurate, but only about 1/8th of an MOA or so. The vast majority of shooters won't notice it or miss it. The advantages of chrome lining a barrel outweigh the disadvantages, IMO. If your budget allows, go for the chrome lining.

As to barrel profile, it depends on what you want the rifle to do. Most M16A2-style ARs come with a 20" "government profile" barrel. Most M4-style ARs come with a 16" barrel that has a notch cut into it for the addition of a grenade launcher. A heavier barrel has more rigidity and is therefore "more accurate," although accuracy is more a function of the shooter than the rifle. Balance is affected somewhat because of the added weight of barrel, but that also depends on the type of stock on the AR to counter balance it. (M4 w/collapsible stock and shorter buffer tube weighs less than an M16A2 stock/buffer.)

All three companies you mentioned make a good product and stand behind their warranties fully. Another quality company I should mention is Rock River Arms. They, too, offer a wide variety of AR rifles and carbines.

Mike

redneck2
May 17, 2006, 07:03 AM
I used to wonder why the owners got so torqued up over AR's. I'm not a military rifle guy. Bolt actions, good glass, accurate shooting for me. The idea of an overpriced military semi-auto that throws bullets all over the place seemed kinda silly.

one of my friends had a Bushie Varminter and shot some exceptional groups. I found a great deal on one at the gun shop so I decided to get it for prarie dogging. The groups it shoots are nothing short of incredible. Understand that it's got the free floated match barrel, 2 stage match trigger, 6.5x20 Leupold and I'm using handloads. We shot 2 consecutive sub 1" groups at a lasered 268 yards. I think that should answer the question about accuracy from a standard weight barrel.

I think before anyone can give a reasonable reply, you might want to figure out what you're gonna do. Just precision targets, varmints, general blasting, HD?

chevrofreak
May 17, 2006, 07:57 AM
Not an AR fan so I probably have little business posting in this thread..... but, why not a stainless barrel?

Zak Smith
May 17, 2006, 11:37 AM
A chrome-lined barrel will give a little more corrosion resistance, which is an issue if you take your rifle swimming and cannot clean it for days on end.

Otherwise, SS or CM are good to go. Most barrels are vastly over-cleaned.

-z

P0832177
May 17, 2006, 01:18 PM
What do you want the AR for?

When you buy a whole rifle you pay a FET that ups the price

Build the lower yourself, or buy a complete lower STAG, RRA, Superior are all good.


Varmints? I would buy a DPMS upper from Midway as they have the cheapest prices on varmint uppers. RRA is not a bad choice, but the wait time has gotten a bit long!

Self Defense? SLR is the real deal!
http://www.slr15.com/ plus Sully will show you how to use it as part of the price! A win win situation!

NRA Highpower skip all and get John H. at White Oak Precision www.whiteoakprecision.com to build you one!

SomeKid
May 17, 2006, 02:59 PM
I cannot remember if my AR is chrome moly, or chrome lined. What is the difference?

Zak Smith
May 17, 2006, 03:02 PM
Chrome Moly = a type of steel alloy which contains chromium and molybdenum ("chrome moly")

Chrome lining = hard-chrome plating over a material

SomeKid
May 17, 2006, 03:07 PM
Thanks Zak.

My knowledge of metallurgy is somewhere around non-existant. Here is what it sounds like, and if anyone knows the truth feel free to correct me.

The moly is a slightly weaker barrel, with some resistance to corrosion. The lining is the strong steel barrel with a lot of resistance to corrosion. It sounds like the lining is better. Am I right?

Zak Smith
May 17, 2006, 03:17 PM
No.

You basically get two choices for rifle barrel materials:

1. chrome-moly steel, typically of the 4140 or 4150 variety.

2. stainless steel, typically of the 416 variety.

There are various differences in the materials' properties and the ease of doing machine-work on them.

Military barrels are usually of the chrome-moly variety to maximize ultimate strength and ability to handle heat at low weight.

Match barrels are usually of the stainless variety due to how heat erosion occurs in the throat area (a surface property of the material).

Chrome-lining can be done to either type. It is totally separate and not related to the strength of the barrel of it alloy type.

Chrome-lining is typically done to military barrels of the chrome-moly variety to decrease corrosion and increase barrel life. A chrome coating is very thin-- about 0.0005 inch (according to the Tripp Research web page).

Chrome lining is not structural, it is purely a surface treatment.

raz-0
May 17, 2006, 04:53 PM
HBAR's, to the best of my knowledge, are the product of hi-power competitions. .223 may not be mcuh in the recoil department, but they seem to like their HBAR barrels and lead weights in the stock in that sport.


For an all around general purpose ar, I find a 16" hbar that has been fluted or a 20" "government" profile barrel to handle nicely, not be too heavy, and have good accuracy. Both balance reasonably in a loaded rifle. The 20" is cheaper and a bit more versatile.

Just my $0.02, it's an opinion thing as I know people who think anything that isn't beastly front heavy with a bull barrel. It's a matter of taste and application.

deolexrex
May 17, 2006, 05:41 PM
What are the pros and cons of the 16" vs. the 20"?

Harry Tuttle
May 17, 2006, 05:51 PM
16s won't mount a bayonet properly
20s are too long for poking zombies in the foyer

Zak Smith
May 17, 2006, 05:55 PM
I'm pretty sure a 16" with midlength gas system will mount a bayonet properly.

JNewell
May 17, 2006, 08:38 PM
What are the pros and cons of the 16" vs. the 20"?

Principally velocity vs. handling in tighter spaces. IIRC, even the 20" AR-15 is about the same overall length as, say, a Winchester 94, which is generally considered a pretty handy rifle.

648E
May 17, 2006, 10:28 PM
A 16" mid-length will mount a bayonet the same as a 20" rifle, correct.

Taking a 20" bbl Winchester Model 94 against a 20" AR with fixed stock, the AR is 1/8" longer.

blackhawk2000
May 17, 2006, 10:48 PM
More velocity in a 20". Velocity is your friend, when shooting people with an AR. The shorter the barrel, the closer you have to shoot people.


Now before anyone jumps on my back, I'm not saying getting shot at 200 yds, with a 14.5 barrel would be nothing. But if I had to shoot someone at 200 yds, I would rather shoot them with a 20" barrel than a 14.5" barrel. Read this: http://www.ammo-oracle.com/ for a better ammo understanding.

Harry Tuttle
May 17, 2006, 11:39 PM
it's more likely you will be poking foyer zombies, then taking 200 yard headshots

Lebben-B
May 18, 2006, 04:51 AM
20" Barrel

+ A longer barrel means more velocity for the round. This tranlates into a longer effective range. For example, an M16A2 w/a 20" barrel has a max effective range of 550m. An M4 with a 14.5" barrel has a max effective range of 500m.

+ A 20" barrel will also give you a longer sight radius (In a nutshell, sight radius is the distance between the front and rear sights.) This adds to the accuracy of the iron sights on the rifle.

- A 20" barrel will add to the overall length of the rifle, making it somewhat cumbersome to handle in tight spaces.

16" Barrel

+ A 16" barrel makes for a handy carbine style AR, if the gun is to fulfill an HD/SD role.

+ The 16" barrel is the shortest barrel allowed without paying extra money and dealing with extra paperwork registering a Short Barrled Rifle (SBR) or having a permanently mounted compenstor/muzzle brake that brings the overall length of the barrel to 16".

- Shorter sight radius.

- Slightly heavier recoil impulse.

Mike

rino451
May 18, 2006, 02:28 PM
Couple of points. .223 vs. 5.56. I personally went 5.56 on both sacrificing accuracy for easy feeding - 5.56 will safely take either .223 or 5.56 making surplus 5.56 feasible (safe).

Also, regarding velocity and barrels from ammo oracle and fragmentation, that's all well and good for those who have to stick with military ammo. The rest of us can use soft points or TAP or NBT's or whatever else we can find to do the job better than the military ammo making velocity and therefore barrel length a minor concern. Velocity is a necessary constraint only for the military or those depending on military or NATO ammo.

engineer151515
May 18, 2006, 02:45 PM
I have two 16" AR's. One is an M4 - the other is a Bushmaster HB configuration.


The M4 is lighter and a better "balanced" rifle package. It's my first parts build and holds some sentimenal value for me.
Both shoot well but for some reason that Bushmaster HB really nails the targets. Again, probably more a function of the shooter than the rifle.

blackhawk2000
May 18, 2006, 10:14 PM
In response to using mil ammo vs. commercial ammo, and different wheights in different barrel lengths: http://www.actshooters.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=9;t=000011;p=0&r=nfx&s=noprofile

There are several perspectives that have been given and loads of anecdotes. Here is what I know (five years working for Remington Arms as an engineer is in the background as well as 30 years of watching this stuff):

How many times have you heard of a deer being well hit with a .27 to .35 cal rifle, it runs off, and after some careful tracking, is found hit through the lungs and dead, sometimes several hundred yards away? Even good hits do not always translate to fast stops. Scale down from deer and .30-'06 Springfield to .223 Remington and humans, and ask yourself if we should expect instant stops all of the time.

When the AR15 first got much use in RVN, intelligence info showed us that NVA and VC personnel were in awe of the little 55 grain bullet. When hit, the VC and NVA seemed to fall out of the fight pretty quick. Then they found out that the little rifle had reliability issues and that the soldiers and Marines of the era taught spray and pray, and altered tactics in the hope that they could find the holes in the perimeter were a gun was down.

Long before Mogadishu, the reliability issues got ironed out, marksmanship returned to the training, and we got all obsessed with defeating Soviet soldiers' body armor. We went from a round that tumbled and broke in two after impact to a round that stays point on and in one piece. It might perform better on armored enemies, but it might have been expected to give up something on unarmored opponents. The compromise was thought to be a reasonable one.

Then in Mog, there was that famous pitched battle and numerous other smaller actions. And stories of bad guys taking a hit and keeping going after being shot by a Delta or Spec Ops guy with an M4 fed with 62 grain. There were other stories of it taking four bad guys to get an RPG or MG across a street, with each one dropped by a Ranger or Mountain Division soldier using his M16-A2 and 62 grain ammo.

Scroll forward to Afghanistan, and most of the soldiers over there were toting M-4's and 62 grain ammo and complaining about hitting someone and not dropping him right away. Are we getting anything like a correlation yet?

Some other stories came out about guys carrying the Federal Police load with a hollow point 55 grain bullet in house busts, both in the States and in Asia. And having instant stops most of the time. One story from the 'ghan had a guy fire twelve rounds at six bad guys, with twelve hits and all six dead where they were hit.

And then there are the 77 grain thin jacket target bullets cannellured and loaded as a new government round. And the stories are that it stops things just fine.

Hmmm, I see several things that might be true and appear to be supported by a lot of evidence:

55 FMJ Ball bullets seemed to work fine;
14.5 inch barrels and 62 grain ammo do not seem to go together as well as other loads;
20 inch barrels and 62 grain ammo do seem to work OK;
55 grain hollow point bullets seem to work fine in shorter barrels;
77 grain bullets seem to work fine in shorter barrels.

Hmm, it looks more and more like the 62 grain bullet and rifle length barrels might be OK for war with the Soviets. For Police or Counter-Insurgency Warfare using short barrels, the 62 grain bullet might be a lesser choice than either the 55 grain battle bullet or any of a variety of hollowpoint bullets.

So, believe what you want about bullets. I think that there is more to the story, just based upon the info that is out there. If you have a 20" rifle, it won't matter much what you shoot as long as you perforate the middle of the target. If you have to poke holes in a building or body armor to get at the bad guys, I hope that you have steel penetrator rounds. Otherwise, I hope that you have regular bullets. Either way, I hope that you hit the middle when you need to, or it will all be for naught. Maybe having a mag or three with AP ammo in your kit is not a bad idea. If you want something that both beats armor and works on soft targets, well, there are always battle rifles in 7.62 NATO and .30 Cal M-1.

Billski

If you enjoyed reading about "AR question" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!