BerettaNut92
Member
- Joined
- Dec 23, 2002
- Messages
- 9,723
How do those thin thin, fluted, M4-profile and heavy barrels compare? Any real difference between them weight and performance-wise or are they cosmetic?
AR15s: Fluted vs M4-Profile Barrel?
- Thread starter BerettaNut92
- Start date
- Status
I have not had a fluted model but I have had several 16" heavy barrels. Both of mine now have 16" M4 profile barrels. The M4 profile feels lighter and balances much better. I have not noticed any difference in their performance.
Godd luck, Mike
Godd luck, Mike
yankytrash
Member
I think that without long strings of crazy rapid fire or full auto, you're going to find no difference whatsoever. I'm gonna go out on a limb and say it's all just cosmetic for the typical shooter.
That said, I had a 16" lightweight and an HBAR at the same, at one point in my life. I do have to say that the lightweight couldn't handle a long day at the 200m target like the HBAR could. Once the lightweight heated up, she just couldn't hold her groups as well.
Unless you're planning on purchasing the 203 for the M-4 profile, why bother, eh? It could only get embarassing for ya later.
That said, I had a 16" lightweight and an HBAR at the same, at one point in my life. I do have to say that the lightweight couldn't handle a long day at the 200m target like the HBAR could. Once the lightweight heated up, she just couldn't hold her groups as well.
Unless you're planning on purchasing the 203 for the M-4 profile, why bother, eh? It could only get embarassing for ya later.
Art Eatman
Moderator In Memoriam
Gale McMillan's opinion was "cosmetic". Now, if the main barrel tube is very thin, the flutes might help...
Art
Art
Fluting seems to be a compromise stiffer than a barrel of comparable weight (don't want to start a fluting thread war) with better cooling than either a lightweight or a HBAR. I have a 16 inch "M4" on my AR and don't like the weight forward, of course i have a surefire light mounted to my HG. My next barrel will be either a bushmaster lightweight 16 or maybe a fluted. I like to be able to do mag changes etc while using my firing hand alone to hold on target. Someone on another board posted this recently from bushmasters website, note it doesn't show their lightweight 16 barrel:
BARREL WEIGHTS...
For informative purposes (and because we answer these questions all the time!) here are the comparative weights of our barrels.
All weights are in pounds (for a milled front sight, subtract 0.2 lbs.)
10" - Heavy Bbl. - 2.0 / Fluted Bbl. - 1.9
11.5 " - Heavy Bbl. - 2.2 / Fluted Bbl. - 2.0
11.5x5.5" - Heavy Bbl. - 2.6 / Fluted Bbl. - 2.5
14.5" - Heavy Bbl. - 2.5 / Fluted Bbl. - 2.2
14AK" - Heavy Bbl. - 2.7 / Fluted Bbl. - 2.4
14VO" - Heavy Bbl. - 2.7 / Fluted Bbl. - 2.4
16" - Heavy Bbl. - 2.7 / Fluted Bbl. - 2.3
16 Dissipator" - Heavy Bbl. - 3.0 / Fluted Bbl. - 2.6
20" - Heavy Bbl. - 3.5 / Fluted Bbl. - 3.0
24" - Heavy Bbl. - 3.9 / Fluted Bbl. - 3.1
26" - Heavy Bbl. - 4.0 / Fluted Bbl. - 3.2
And our Military style barrels...
XM177 Bbl. - 1.7 lbs.
M4 Bbl. - 2.0
M4AK Bbl. - 2.2
M4VO Bbl. - 2.2
M4 Dissipator Bbl. - 2.3
20A2 Bbl. - 2.5
BARREL WEIGHTS...
For informative purposes (and because we answer these questions all the time!) here are the comparative weights of our barrels.
All weights are in pounds (for a milled front sight, subtract 0.2 lbs.)
10" - Heavy Bbl. - 2.0 / Fluted Bbl. - 1.9
11.5 " - Heavy Bbl. - 2.2 / Fluted Bbl. - 2.0
11.5x5.5" - Heavy Bbl. - 2.6 / Fluted Bbl. - 2.5
14.5" - Heavy Bbl. - 2.5 / Fluted Bbl. - 2.2
14AK" - Heavy Bbl. - 2.7 / Fluted Bbl. - 2.4
14VO" - Heavy Bbl. - 2.7 / Fluted Bbl. - 2.4
16" - Heavy Bbl. - 2.7 / Fluted Bbl. - 2.3
16 Dissipator" - Heavy Bbl. - 3.0 / Fluted Bbl. - 2.6
20" - Heavy Bbl. - 3.5 / Fluted Bbl. - 3.0
24" - Heavy Bbl. - 3.9 / Fluted Bbl. - 3.1
26" - Heavy Bbl. - 4.0 / Fluted Bbl. - 3.2
And our Military style barrels...
XM177 Bbl. - 1.7 lbs.
M4 Bbl. - 2.0
M4AK Bbl. - 2.2
M4VO Bbl. - 2.2
M4 Dissipator Bbl. - 2.3
20A2 Bbl. - 2.5
IMO they handle completely differently. The fluted is a little heavier and I can feel it. The M4 is tapered under the handguards. This lead to lightning fast handling and great balance in my experience. The heavy barrels, even the fluted ones, feel bad to me.
FNFiveSeven
Member
- Joined
- Jan 3, 2003
- Messages
- 538
I've got the fluted, free-floated 16" bbl and it's one of the lightest, best handling rifles I've ever shot. I love it!
Steve Smith
Moderator Emeritus
IIRC, Gale said that more often than not the flutes were put i nat the wrong time in reference to the heat treating of the barrel and accuracy was often negatively affected by the flutes.
yankytrash
Member
Sorry about the bump, this is a test. Mods may delete this post.
bad_dad_brad
Member
I researched the beejeezzus out of this subject awhile ago.
I found that the best compromise was a 16" HBAR. Not perfect. But it is handy, not too heavy, balances well, is accurate, and robust. Note that I do not include the Bushy Dissipator, as this 16" AR feels nose heavy to me.
I think that 20" HBARs are best left for target shooting. And 14.5" barrels of any kind lose too much energy past 100 yards. However to make them legal, ya got to weld a compensator on it, making it 16" long anyway, and LOUD! What is the point?
There is much debate over fluting. After researching this subject, I think fluting is cool looking, but there is little advantage, if any, in doing so.
Sigh, this subject has been debated over and over. So my advice to you my THR brothers and sisters, is to have multiple AR uppers! That is my plan. Started with the 16" A2, the next is a 24" flat top varminter. Takes only seconds to make a new rifle.
I found that the best compromise was a 16" HBAR. Not perfect. But it is handy, not too heavy, balances well, is accurate, and robust. Note that I do not include the Bushy Dissipator, as this 16" AR feels nose heavy to me.
I think that 20" HBARs are best left for target shooting. And 14.5" barrels of any kind lose too much energy past 100 yards. However to make them legal, ya got to weld a compensator on it, making it 16" long anyway, and LOUD! What is the point?
There is much debate over fluting. After researching this subject, I think fluting is cool looking, but there is little advantage, if any, in doing so.
Sigh, this subject has been debated over and over. So my advice to you my THR brothers and sisters, is to have multiple AR uppers! That is my plan. Started with the 16" A2, the next is a 24" flat top varminter. Takes only seconds to make a new rifle.
FNFiveSeven
Member
- Joined
- Jan 3, 2003
- Messages
- 538
uhhh, just some comments
Fluted barrels don't bend when you trip and fall on them, the strength to weight ratio of a fluted barrel is best, this is not opinion, just the way it is. Yes, it is weaker than an Hbar, but IMO Hbar is overkill, especially on a short barrel like the 16" where you cannot exert as much torque on the barrel when you fall on it as you can with a 20 or 24" bbl.
Additionally... HS precision builds most of their top of the line rifles with fluted barrels, and they are some of the most accurate, if not THE MOST ACCURATE 308's in the world... so I can hardly believe that fluted barrels are detrimental to accuracy. It may not help much, but I believe it has at least been shown that they do not hurt.
Fluted barrels don't bend when you trip and fall on them, the strength to weight ratio of a fluted barrel is best, this is not opinion, just the way it is. Yes, it is weaker than an Hbar, but IMO Hbar is overkill, especially on a short barrel like the 16" where you cannot exert as much torque on the barrel when you fall on it as you can with a 20 or 24" bbl.
Additionally... HS precision builds most of their top of the line rifles with fluted barrels, and they are some of the most accurate, if not THE MOST ACCURATE 308's in the world... so I can hardly believe that fluted barrels are detrimental to accuracy. It may not help much, but I believe it has at least been shown that they do not hurt.
It's funny how we all perceive weight so differently...
I have a 14.5" fluted HBAR. It feels much lighter than a standard HBAR. My buddy has the "M4" profile. The overall weight is very similar, but the "feel" is different. The M4 feels muzzle heavy, since all the weight is out past the front sight. The fluted barrel's weight is uniform all the way down, so it feels much more balanced to me.
There is no accuracy difference between my fluted and buddy's M4... Mine just feels lighter when you hold it in the firing position.
Because I prefer a lightweight rifle, I would easily choose fluting over the other 2 options again. Definitely more than just "looks".
If a thin AND fluted barrel exists, I certainly wouldn't want one.
But mine's pre-ban... And again, I don't like 16" + flash supressor look. The 14.5" with 2" FS is 1" shorter than a 16" with 1.5" FS.... Now, if the mid-length handguard shorties like RRA offers had been around when I got this upper, I'd have gotten on of those instead.
Besides, what's the point of having a bayonet lug if you can't attach a bayonet, right
I have a 14.5" fluted HBAR. It feels much lighter than a standard HBAR. My buddy has the "M4" profile. The overall weight is very similar, but the "feel" is different. The M4 feels muzzle heavy, since all the weight is out past the front sight. The fluted barrel's weight is uniform all the way down, so it feels much more balanced to me.
There is no accuracy difference between my fluted and buddy's M4... Mine just feels lighter when you hold it in the firing position.
Because I prefer a lightweight rifle, I would easily choose fluting over the other 2 options again. Definitely more than just "looks".
I've never seen a "thin fluted barrel". I've seen thin barrels, and I've seen thick HBARS that have been fluted. I believe Skunk was asking about THIN barrels, FLUTED Barrels, M4 Barrels, etc...
If a thin AND fluted barrel exists, I certainly wouldn't want one.
If it's a post-ban rifle, I agree. I guess it's a personal preference, but I don't like the looks of a 16" barrel PLUS something on the end... it's just too long looking. The best looking (IMHO) post-ban 16" rifle is the Rock River with the counter sunk flash supressor. It looks like a 14.5" barrel with flash supressor, but the barrel comes all the way out to the end (16").
But mine's pre-ban... And again, I don't like 16" + flash supressor look. The 14.5" with 2" FS is 1" shorter than a 16" with 1.5" FS.... Now, if the mid-length handguard shorties like RRA offers had been around when I got this upper, I'd have gotten on of those instead.
Besides, what's the point of having a bayonet lug if you can't attach a bayonet, right
yankytrash
Member
While we're on the topic, isn't the fluting only to provide more surface area for cooling? At least, that's what I always thought.
Badger Arms
Member
Yank:
No, the fluting does a few things. The first and most important reason to flute is the lower weight to stiffeness ratio. A 3 pound fluted barrel will be stiffer than a 3 pound unfluted barrel. It will also have more surface area than either the 3 pound unfluted barrel or the 3.5 pound barrel of the same diameter as the fluted barrel but without the flutes.
I'll try to correct a falacy that people seem to have. Fluting makes a barrel weaker and less stiff than its pre-fluted condition. It does, however lower the weight and increase heat dissipation. When comparing barrels of the same weight, the fluted barrel will always be stiffer and cool faster. A fluted barrel is less likely to bend than an unfluted barrel of the same weight. Fluted barrels are heavier than unfluted barrels of the same effective diameter (the bottom of the flutes).
The heat dissipation is not that great of a factor. What you get with lengthwise flutes is a 'cushion' of hot air near the barrel. The natural action of circulated air goes up the barrel, perpendicular to the flutes. The flutes trap pockets of warm air in them and the cooling effect is minimized. The barrel will cool faster than either an HBAR or Light barrel... BUT... there is another factor to consider.
Barrel cooling is not as important as heat dissipation. The point is to get the heat away from the bore and spread along the mass of the barrel. Steel transmits heat much faster than does air. A lighter barrel (fluted or unfluted) has a smaller total mass. When you have a lighter barrel, it will heat up to a higher temperature much faster than a heavy or bull barrel. A string of 90 rounds will make a fluted barrel hotter than a heavy barrel. Yeah, the fluted barrel will cool faster but it will get hotter first. Understand? This means that for heat dissipation, you look at the weight of the barrel and nothing else.
It is therefore reasonable that a fluted barrel is primarily for getting a light barrel that's a bit stiffer than a barrel of equal weight. Me... I bought a thin taper barrel. I've got patience and other guns to shoot while it cools down. It's good for about 60-90 rounds at the rate I shoot at before I set it down to cool.
No, the fluting does a few things. The first and most important reason to flute is the lower weight to stiffeness ratio. A 3 pound fluted barrel will be stiffer than a 3 pound unfluted barrel. It will also have more surface area than either the 3 pound unfluted barrel or the 3.5 pound barrel of the same diameter as the fluted barrel but without the flutes.
I'll try to correct a falacy that people seem to have. Fluting makes a barrel weaker and less stiff than its pre-fluted condition. It does, however lower the weight and increase heat dissipation. When comparing barrels of the same weight, the fluted barrel will always be stiffer and cool faster. A fluted barrel is less likely to bend than an unfluted barrel of the same weight. Fluted barrels are heavier than unfluted barrels of the same effective diameter (the bottom of the flutes).
The heat dissipation is not that great of a factor. What you get with lengthwise flutes is a 'cushion' of hot air near the barrel. The natural action of circulated air goes up the barrel, perpendicular to the flutes. The flutes trap pockets of warm air in them and the cooling effect is minimized. The barrel will cool faster than either an HBAR or Light barrel... BUT... there is another factor to consider.
Barrel cooling is not as important as heat dissipation. The point is to get the heat away from the bore and spread along the mass of the barrel. Steel transmits heat much faster than does air. A lighter barrel (fluted or unfluted) has a smaller total mass. When you have a lighter barrel, it will heat up to a higher temperature much faster than a heavy or bull barrel. A string of 90 rounds will make a fluted barrel hotter than a heavy barrel. Yeah, the fluted barrel will cool faster but it will get hotter first. Understand? This means that for heat dissipation, you look at the weight of the barrel and nothing else.
It is therefore reasonable that a fluted barrel is primarily for getting a light barrel that's a bit stiffer than a barrel of equal weight. Me... I bought a thin taper barrel. I've got patience and other guns to shoot while it cools down. It's good for about 60-90 rounds at the rate I shoot at before I set it down to cool.
EXCELLENT explanation, BadgerArms!
My only reason for getting the fluted barrel was lighter weight without the M4 profile.
My Bushmaster shorty came with an 11.5" barrel and 5.5" flash supressor. It was very light, but once I learned the severe handicap that the 11.5" barrel was, I wanted a longer barrel. The first time I picked up a 16" HBAR, it felt like the handguards were loaded with cement compared to what I was used to. Flutes got me closest to the same weight. Since "heavy" and "light" are obviously subjective, if you consider the 16" HBAR to be "light", then flutes are completely unneccessary.
Kurt's Kustom Firearms is supposed to be doing great things with the weight on AR's. I don't have any personal experience (yet), but Redleg says good stuff about him, as do many folks on AR15.com.
I've always thought that there should be a "medium" weight barrel, that was the same diameter from one end to the other, rather than EXTRA fat under the handguards.
My only reason for getting the fluted barrel was lighter weight without the M4 profile.
My Bushmaster shorty came with an 11.5" barrel and 5.5" flash supressor. It was very light, but once I learned the severe handicap that the 11.5" barrel was, I wanted a longer barrel. The first time I picked up a 16" HBAR, it felt like the handguards were loaded with cement compared to what I was used to. Flutes got me closest to the same weight. Since "heavy" and "light" are obviously subjective, if you consider the 16" HBAR to be "light", then flutes are completely unneccessary.
Kurt's Kustom Firearms is supposed to be doing great things with the weight on AR's. I don't have any personal experience (yet), but Redleg says good stuff about him, as do many folks on AR15.com.
I've always thought that there should be a "medium" weight barrel, that was the same diameter from one end to the other, rather than EXTRA fat under the handguards.
Redlg155
Member
Ahh..the quest of the ultimate rifle.
Fluted barrels are really nice, but I don't see a necessity in having one for the average user. Nor do I see heavy barrels a plus in Carbine size rifles. A carbine should be light and handy. The "pencil" type barrels favor this type of rifle.
As for differences in feel, even M4 style rifles from different manufacturers will feel different. Some are the type with a decreased diameter under the handguards. Others such as JT Dist models are standard HB weight under the handguards with the M4 profile past the front sight base. You even have variances within manufacturers . Rock River produced some with the smaller diameter under the handguards and then later produced some "updated" ones with heavier diameters under the handguards.
I haven't personally seen any problems with smaller profile barrels. I've fired my old issued M16A1 until the gas tube was cherry red and the handguards were too hot to hold without gloves. Then later took the same rifle and qualified with it on the range. That's good enough for me.
I once made the mistake of carrying a Bushmaster Shorty AK model on a hunting trip. Strange how I used to carry my issued M16 all day with no problems, but a little ol shorty AR hung like a rock on my shoulder and just about killed me.
Onslaught,
Take a peek at Kurts page when you get a chance. He's doing a really neat "Ultralite Karbine" for GWLE magazine.
Good Shooting
RED
Fluted barrels are really nice, but I don't see a necessity in having one for the average user. Nor do I see heavy barrels a plus in Carbine size rifles. A carbine should be light and handy. The "pencil" type barrels favor this type of rifle.
As for differences in feel, even M4 style rifles from different manufacturers will feel different. Some are the type with a decreased diameter under the handguards. Others such as JT Dist models are standard HB weight under the handguards with the M4 profile past the front sight base. You even have variances within manufacturers . Rock River produced some with the smaller diameter under the handguards and then later produced some "updated" ones with heavier diameters under the handguards.
I haven't personally seen any problems with smaller profile barrels. I've fired my old issued M16A1 until the gas tube was cherry red and the handguards were too hot to hold without gloves. Then later took the same rifle and qualified with it on the range. That's good enough for me.
I once made the mistake of carrying a Bushmaster Shorty AK model on a hunting trip. Strange how I used to carry my issued M16 all day with no problems, but a little ol shorty AR hung like a rock on my shoulder and just about killed me.
Onslaught,
Take a peek at Kurts page when you get a chance. He's doing a really neat "Ultralite Karbine" for GWLE magazine.
Good Shooting
RED
Redleg, what does this Ultralite Karbine consist of ? I couldn't find it on the web page. I am trying to put together a super lightweight AR and would be interested in where he was saving weight.
I recently sent Kurt a 16" Bushmaster upper. The original barrel is what I would call a fairly heavy barrel. It is a standard Bushmaster 16" "Shorty". I am having Kurt turn down the barrel to his super lightweight configuration. I am having him trim back the barrel to 15" and installing one of his brakes. I intended to put the upper on a Cavalry Arms plastic lower. I am not really sure the CAV arms lower is any lighter than a standard lower, I haven't put it all together yet.
I recently sent Kurt a 16" Bushmaster upper. The original barrel is what I would call a fairly heavy barrel. It is a standard Bushmaster 16" "Shorty". I am having Kurt turn down the barrel to his super lightweight configuration. I am having him trim back the barrel to 15" and installing one of his brakes. I intended to put the upper on a Cavalry Arms plastic lower. I am not really sure the CAV arms lower is any lighter than a standard lower, I haven't put it all together yet.
Redlg155
Member
444,
Here is a link to the thread in the Industry Section over at AR15.com
http://ar15.com/forums/topic.html?b=2&f=44&t=139487
Looks like most of his weight savings was with the barrel. It looks pretty thin. He also did a custom gas block for a bit more weight savings.
I personally would have went for a standard handguard or a FOBUS type if I wanted some extra weight savings instead of a free floated railed type handguard.
Are you getting the new model CAVARMS lowers? I kinda like the looks of it those as well as the shorter length.
Good Shooting
RED
Here is a link to the thread in the Industry Section over at AR15.com
http://ar15.com/forums/topic.html?b=2&f=44&t=139487
Looks like most of his weight savings was with the barrel. It looks pretty thin. He also did a custom gas block for a bit more weight savings.
I personally would have went for a standard handguard or a FOBUS type if I wanted some extra weight savings instead of a free floated railed type handguard.
Are you getting the new model CAVARMS lowers? I kinda like the looks of it those as well as the shorter length.
Good Shooting
RED
Yeah, I might get the new one, or I might keep the one I have and get the other one also.
I bought a set of CAV arms M4 handguards for the rifle to match the rest of the rifle. I am not sure if this is the lightest configuration though. That is why I am trying to gather ideas for the lightest configuration.
I bought a set of CAV arms M4 handguards for the rifle to match the rest of the rifle. I am not sure if this is the lightest configuration though. That is why I am trying to gather ideas for the lightest configuration.
- Status
