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Posted: 3/1/2010 1:07:13 PM EDT
Hi, I've been rethinking how I'm going to get my first AR. Right now I'm thinking of either getting an upper and complete lower from DSArms with an m4 barrel, or building an HBAR carbine from a Del-ton kit.
My question is this: will the thickness of the barrel make a noticeable difference in accuracy if I'm shooting within 100 yards? I've heard from a lot of sources that the m4 barrels aren't as accurate because they're kinda thin under the handguards. |
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Hi, I've been rethinking how I'm going to get my first AR. Right now I'm thinking of either getting an upper and complete lower from DSArms with an m4 barrel, or building an HBAR carbine from a Del-ton kit. My question is this: will the thickness of the barrel make a noticeable difference in accuracy if I'm shooting within 100 yards? I've heard from a lot of sources that the m4 barrels aren't as accurate because they're kinda thin under the handguards. It isint just M4 barrels, any govt. profile barrel is thin under the handguards... |
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Hi, I've been rethinking how I'm going to get my first AR. Right now I'm thinking of either getting an upper and complete lower from DSArms with an m4 barrel, or building an HBAR carbine from a Del-ton kit. My question is this: will the thickness of the barrel make a noticeable difference in accuracy if I'm shooting within 100 yards? I've heard from a lot of sources that the m4 barrels aren't as accurate because they're kinda thin under the handguards. It isint just M4 barrels, any govt. profile barrel is thin under the handguards... Yeah, I've hard, but I also heard from a del-ton sales rep that their 16" rifle kits are thick under the handguards Regarding the goal for this setup, its mostly going to be a range toy and a home defense gun (and maybe, just maybe, a zombie killer if SHTF) |
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Hi, I've been rethinking how I'm going to get my first AR. Right now I'm thinking of either getting an upper and complete lower from DSArms with an m4 barrel, or building an HBAR carbine from a Del-ton kit. My question is this: will the thickness of the barrel make a noticeable difference in accuracy if I'm shooting within 100 yards? I've heard from a lot of sources that the m4 barrels aren't as accurate because they're kinda thin under the handguards. It isint just M4 barrels, any govt. profile barrel is thin under the handguards... Yeah, I've hard, but I also heard from a del-ton sales rep that their 16" rifle kits are thick under the handguards Regarding the goal for this setup, its mostly going to be a range toy and a home defense gun (and maybe, just maybe, a zombie killer if SHTF) Unless your doing hard core training or shooting 500 meters, It will be fine. |
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If it's a bench gun get the HBAR.
Anything less then that I prefer a govt profile barrel. |
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Hi, I've been rethinking how I'm going to get my first AR. Right now I'm thinking of either getting an upper and complete lower from DSArms with an m4 barrel, or building an HBAR carbine from a Del-ton kit. My question is this: will the thickness of the barrel make a noticeable difference in accuracy if I'm shooting within 100 yards? I've heard from a lot of sources that the m4 barrels aren't as accurate because they're kinda thin under the handguards. It isint just M4 barrels, any govt. profile barrel is thin under the handguards... Yeah, I've hard, but I also heard from a del-ton sales rep that their 16" rifle kits are thick under the handguards Regarding the goal for this setup, its mostly going to be a range toy and a home defense gun (and maybe, just maybe, a zombie killer if SHTF) I doubt you'd notice a difference in accuracy, unless you're handloading and shooting at very long ranges (ie much farther than 100y). You might as well get the M4 barrel and have a lighter rifle. |
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I am the minority here as I prefer the Hbar. The M4 will do fine but for most accuracy allow for proper cooling between rounds and you will be fine. The added weight of a Hbar just doesn't bother me. Good ;Luck.
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If it's a bench gun get the HBAR. Anything less then that I prefer a govt profile barrel. Agree. |
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Prolly won't make a difference off the bench but shooting offhand an Hbar will be more stable thus you won't miss as often. If you carry it long hours between shooting, i.e., patrols or hunting the Gov. profile will be lighter but with a sling my 16" Hbar's weight wasn't a problem not to mention when it came time to shoot, in my case hogs, it was deadly solid on target. In other words I'd rather carry more weight all day and be able to make the shot then carry something lighter and blow it.
Having said that my Gov. profile is pretty damned stable |
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I am the minority here as I prefer the Hbar. The M4 will do fine but for most accuracy allow for proper cooling between rounds and you will be fine. The added weight of a Hbar just doesn't bother me. Good ;Luck. +1 |
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I compromised and went SOCOM weight..lighter than HBAR and heavier than regular M4 profile.15 to 20 rds per minute should not bother accuarcy or get the barrel hot enough to bother it.HBARs take heat better and will stay accuarte longer and hotter than a lighter barrel but it also takes longer too cool down.Just remeber we have semi auto single stage AR15s..most of us dont shoot full auto where accuarcy can really be effected when things heat up way way faster than semi only will.
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I compromised and went SOCOM weight..lighter than HBAR and heavier than regular M4 profile.15 to 20 rds per minute should not bother accuarcy or get the barrel hot enough to bother it.HBARs take heat better and will stay accuarte longer and hotter than a lighter barrel but it also takes longer too cool down.Just remeber we have semi auto single stage AR15s..most of us dont shoot full auto where accuarcy can really be effected when things heat up way way faster than semi only will. IIRC unless I'm mistaken, doesn't slower heat up also help reliability? (Heat being one of the causes of part malfunctions?) |
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Yea thats what I meant by takes the heat better as far as heats up slower I guess it depends on rate of fire.Ive gotten HBARs heated up real quick.I think though with barrel heat always being a fctor in any weapon the AR/M16 also gets hot inside the receiver,just as hot as the barrel so betewwen baking off lube and shitting where its eating I think all that with the barrel can contribute to heat related failures.I never shoot faster than I can keep my sights on target wich is about a round every 2 or 3 seconds.If I were in a survival situation dpepnding on conditions maybe I would or would not have to dump ammo out faster.
Ive nenevr been in situations where Ive had to use fire to move but in a situation like that where your laying down fire the HBAR will get real hot too but being thicker it will function longer and stay rigid better as oposed to a lighter barrel and take longer to cool wich may or may not be a factor depending on the situation.One things for sure if heavier barrels werent better for function the Army wouldnt have listed a heavier barrel as a want for interim M4 upgrades " SOCOM BARREL" along with a piston system..so cooler running upper and internals and a barrel that takes heat better.Isit relevant in semi-auto only operation well we dont really know unless we have some data from say contractors or others who have used semi onlys in prolonged firefights in afghanistan or Iraq and what type of barrel was used.As far as I know right now only SF M4A1s have the heavier med weight Socom barrel. |
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I think going with a free float hand guard will have a greater impact on accuracy than HBAR vs. Govt. profile.
Get govt or M4 profile and then add a free float hand guard, you'll be good to go... |
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Fluted barrels are awesome..I dont like the look of fluting but with the scalopped grooves you get just as much barrel stiffness and actually more surface area than it would have had even as an HBAR so it cools like a lightweight barrel.So like an HBAR fluted barrels give the same benefits with less weight and quicker cooling.
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Many don't like fluted barrels but seem to like the 'dimpled' ones. I like the flutes - there's no question they remove more weight and provide more surface area than dimpling. Dimpling to me is strictly a cosmetic effect. That mutt I made is the only AR I have shot that hit the center at 25 yds with the aperture on the center line of the index. That actually speaks not to my assembly but of the man who built the upper. Plus, like Olympic or not, the one thing they always did well was barrels, and this one is no exception.
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..Regarding the goal for this setup, its mostly going to be a range toy and a home defense gun (and maybe, just maybe, a zombie killer if SHTF) For those goals I'm definately a M4 or 'Lightweight' (A1 profile) fan. Lighter weight rules, especially if you like to shoot off hand or get into carbine matches or classesl |
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Quoted:My question is this: will the thickness of the barrel make a noticeable difference in accuracy if I'm shooting within 100 yards?
No. |
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You guys are such AR snobs, I haven't been able to pull the trigger on my first AR but I will soon!
You guys are having way to much fun! Seems like crack and I don't want that first rock! I'm afraid! I hope the zombies don't come before do it! |
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Fluted barrels are awesome..I dont like the look of fluting but with the scalopped grooves you get just as much barrel stiffness and actually more surface area than it would have had even as an HBAR so it cools like a lightweight barrel.So like an HBAR fluted barrels give the same benefits with less weight and quicker cooling. Are you suggesting that a fluted HBAR has just as much rigidity as a non-fluted HBAR? If so I would have to disagree, anytime you remove material you are going to lose stiffness. The fluted one will cool faster though. |
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I believe rigdity is the same because your only scaloping small trenches not turning down the entire profile to a thinner one so I think rigidity would be the same if not more no?the trenches or flutes are low points but the high points remain I would think those are enough to still provide the same stiffness but less weight in the process.
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I am the minority here as I prefer the Hbar. The M4 will do fine but for most accuracy allow for proper cooling between rounds and you will be fine. The added weight of a Hbar just doesn't bother me. Good ;Luck. +1 if you keep it KISS the added weight is not a problem. all I have on mine is a KAC RAS and a small flashlight...I've used it during a dynamic shooting match and the extra weight helped me to deal with the recoil |
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I believe rigdity is the same because your only scaloping small trenches not turning down the entire profile to a thinner one so I think rigidity would be the same if not more no?the trenches or flutes are low points but the high points remain I would think those are enough to still provide the same stiffness but less weight in the process. Nope, by removing material you are decreasing the sections moment of inertia, or resistance to bending. It's a classic mechanics of materials problem. Whether or not the reduced stiffness has any ill affects is another matter. |
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If you had the same amount of material overall (greater dia) to compensate for the material lost in the flutes then the stiffness would actually be increased! Think flanges of a steel beam being further from the neutral axis! But material removal will result in less stiffness and more bending!
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If you had the same amount of material overall (greater dia) to compensate for the material lost in the flutes then the stiffness would actually be increased! Think flanges of a steel beam being further from the neutral axis! But material removal will result in less stiffness and more bending! You are absolutely correct, however in the case of fluted barrels you are not increasing the diameter, you are removing material from a section of fixed inside and outside diameters, thus decreasing it's Ixx and therefor it's stiffness (resistance to bending around the X-X axis). |
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Taking some materiel away from a barrel does not always result in a less stiff barrel. It depends more on where and how the materiel is taken away. If you take the I beam example the I beam has the same strength as solid box beam of the same dimensions, but with a reduction of @ 50% in weight and materiel. The outside most point of the flutes (the top of the flute) is further away from the neutral plane than a smaller diameter light weight barrel so it will be more rigid in that case. Because it has the same distance from the neutral plane as the heavy barrels profile the stiffness should be the same, for the same reason as the I beam vs. the solid beam but with out the weight penalty.
Seems like something for "The Box of Truth" (you know, the guys that actually know WTF they are talking about when it come to debunking firearms myths unlike those tools from SF with a TV show...) |
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Circulars cross sections such as a tube....such as a barrel is already the most efficient cross section regarding bending. All of the area is located away from the axis of bending and its bending characteristics are the same regardless of what axis you choose. Please remember I said efficient, not strongest or best.....I don't think fluting is going to hurt bending that much one way or another. Considering the increased heat transfer away from your barrel, I think fluting is a great idea. I've sold guns that got hot too quick and stayed hot for too long. I think this thread started as HBAR vs. M4. Wow. I agree Captain, sometimes you gotta pull the physics out.
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I hate too continue on but the square beam theory...fact...etc...you have but although it may be correct its not efficient at all. You quote three times the bending moment but look at area. The square 12.3 x 12.3 = 151.29 in2.
The HP section you provided, 24.6 in2. So basically six times the area was used to get three times the bending resistance. |
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Circulars cross sections such as a tube....such as a barrel is already the most efficient cross section regarding bending. All of the area is located away from the axis of bending and its bending characteristics are the same regardless of what axis you choose. Please remember I said efficient, not strongest or best.....I don't think fluting is going to hurt bending that much one way or another. Considering the increased heat transfer away from your barrel, I think fluting is a great idea. I've sold guns that got hot too quick and stayed hot for too long. I think this thread started as HBAR vs. M4. Wow. I agree Captain, sometimes you gotta pull the physics out. And I agree with you 100%, the benefits of fluting out weigh the minor loss in in bending resistance. I was just correcting the others who were suggesting that there is no loss at all in bending resistance. |
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Yep...anytime you take area away from a section's extremities, bending is compromised. Consider an I Beam. Now chop of the top flange. You decreased area by roughly a third but decreased the bending moment by almost half. The area is oriented away from the axis of bending for a reason. Captain, what do you do...I've never seen someone pull out the second moment of area on a gun forum before.
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I hate too continue on but the square beam theory...fact...etc...you have but although it may be correct its not efficient at all. You quote three times the bending moment but look at area. The square 12.3 x 12.3 = 151.29 in2. The HP section you provided, 24.6 in2. So basically six times the area was used to get three times the bending resistance. We weren't discussing area and amount of material, but stiffness. This all started when I corrected "Chromelined's" comment about fluting not reducing stiffness, that is all. Quote: "Fluted barrels are awesome..I dont like the look of fluting but with the scalopped grooves you get just as much barrel stiffness and actually more surface area than it would have had even as an HBAR so it cools like a lightweight barrel.So like an HBAR fluted barrels give the same benefits with less weight and quicker cooling." |
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I hate too continue on but the square beam theory...fact...etc...you have but although it may be correct its not efficient at all. You quote three times the bending moment but look at area. The square 12.3 x 12.3 = 151.29 in2. The HP section you provided, 24.6 in2. So basically six times the area was used to get three times the bending resistance. We weren't discussing area and amount of material, but stiffness. This all started when I corrected "Chromelined's" comment about fluting not reducing stiffness, that is all. I know. I understand. I just can't help but think with efficiency in mind. You know this economy has got everything thinking efficiency around here. What field you work in? I've never seen someone pull out the second moment of area on a gun forum before. |
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Captains1911 must be an engineer or had training in it! I'm an Architect so we have these discussions with our Structural Engineer all the time about Structures~~~~ Barrels not so much but the physics is still the same.
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I recently bought a 16" carbine HBAR upper. It's going to be my abuse upper. Little cleaning & lots of rapid fire mag dumps.
Upon putting it on my lower I did notice the weight difference. It's not much but you do feel it. Adding an eotech & MBUS balanced it out a little. Under the had guards is THICK. There's almost no space between it & the gas tube. |
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Captains1911 must be an engineer or had training in it! I'm an Architect so we have these discussions with our Structural Engineer all the time about Structures~~~~ Barrels not so much but the physics is still the same. |
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Many don't like fluted barrels but seem to like the 'dimpled' ones. I like the flutes - there's no question they remove more weight and provide more surface area than dimpling. Dimpling to me is strictly a cosmetic effect. That mutt I made is the only AR I have shot that hit the center at 25 yds with the aperture on the center line of the index. That actually speaks not to my assembly but of the man who built the upper. Plus, like Olympic or not, the one thing they always did well was barrels, and this one is no exception. dimpling, when done properly(knights) removes more weight, is more rigid, and offers more cooling than fluting. Its better in every aspect which is why they do it. I doubt knights does stuff soley for looks. |
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Captains1911 must be an engineer or had training in it! I'm an Architect so we have these discussions with our Structural Engineer all the time about Structures~~~~ Barrels not so much but the physics is still the same. Yeah I jumped over from the private side to a public utility about 2 years ago so it's been a long time since I actually practiced...engineering that is....I shot off about 200 yesterday. |
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16" Midlength Govt. Profile 1:7" Chrome Lined.
or 20" Govt. Profile 1:7" Chrome Lined. |
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