Dimpling a barrel [Archive] - M4Carbine.net Forums

bubba04

11-18-10, 18:34

I am thinking of making a rifle. Looking at using a BCM 18" SS barrel. I am thinking of having the barrel dimpled or fluted to drop the weight some, as I plan to use the rifle in the carbine roll.

Do yall know how much weight reduction I can get by dimpling the barrel or having it fluted? I would think with the dimpling the barrel would cool much faster because of the added surface area. is that correct?

thanks.

mkmckinley

11-18-10, 18:49

You're not going to see a crazy difference from fluting unless you're starting out with a heavy barrel to begin with. You might email ADCO and ask about the weight difference. Have you considered one of the .625 lightweight barrels from like DD or BCM?

bubba04

11-18-10, 19:23

What I am lookin for I think....is a 18 inch rifle length gas system barrel. The one I am lookin at is a medium profile. I have considered a light weight barrel but have decided against it.

ALCOAR

11-18-10, 19:24

If you want the most weight shaved off you need to recontour or reprofile the diameter of your barrel vs. fluting or dimpling. You will hear many arguments from both sides of the spectrum in terms of what the potential effects are of performing these mods to a barrel.

If I were going to do it I would let the guy who does the KAC barrels do it in their proprietary pattern.

bubba04

11-18-10, 19:32

Do you happen to have the contact info of who does their work or know who does it?

ALCOAR

11-18-10, 19:40

PM sent

the_accuser

11-18-10, 21:30

Like Trident said, recontouring the barrel will reduce the most weight but the dimpling does look cool or at least I like it. Here is a few pics of a rifle I had ADCO recontour the barrel under the handguard and dimple the front end. Turned out great and a good bit lighter, balances out really nice.

http://i41.photobucket.com/albums/e251/the_accuser/mrpr1.jpg
http://i41.photobucket.com/albums/e251/the_accuser/mrpr2.jpg
http://i41.photobucket.com/albums/e251/the_accuser/mrpr3.jpg
http://i41.photobucket.com/albums/e251/the_accuser/b1.jpg

ALCOAR

11-18-10, 21:44

^^^^one of my favorite rifles^^^^

esp. considering how it changes form so nicely in your hands;)

Belmont31R

11-18-10, 22:21

bubba04

11-19-10, 06:31

Accuser, that does look real good. Is that a 16" barrel?

Are there any downsides to having your barrel dimpled?

royta

11-19-10, 06:41

If you are just looking for a lightweight SS barrel have you considered the Noveske Rogue Hunter upper? http://noveskerifleworks.com/cgi-bin/imcart/display.cgi?item_id=18rh-556&cat=124&page=1&search=&since=&status=

It says right in the description found in the link that the barrel is an 18" SPR, which I believe is 2lb 8oz. I believe that is the common weight of 18" SPR profiled barrels. The overall weight of the Noveske upper is the the same, if not more than almost every one of the BCM 18" SS410 uppers. http://www.03designgroup.com/technotes/ar15-upper-receiver-weight-comparisons

ETA - The Noveske weight may include BCG and CH. I didn't pay enough attention to tell.

the_accuser

11-19-10, 06:49

Accuser, that does look real good. Is that a 16" barrel?

Are there any downsides to having your barrel dimpled?

Yep, 16" barrel. I haven't found any downsides after having the barrel dimpled. Matter of fact I sent ADCO another one (10.5") shortly after to be dimpled under the handguard.

http://i41.photobucket.com/albums/e251/the_accuser/dsbr1.jpg
http://i41.photobucket.com/albums/e251/the_accuser/dsbr3.jpg
http://i41.photobucket.com/albums/e251/the_accuser/mrpcqb2.jpg

caelumatra

11-19-10, 08:17

^^

That's sexy as hell!

natdm

11-19-10, 10:41

God damn that looks good.

Doesn't dimpling the barrel help with heating? Something about more surface space?

mbogo

11-19-10, 10:54

I can see the benefit of weight savings, but does dimpling impart stress to the barrel, and does that affect the harmonics to the point where accuracy is adversely affected?

mbogo

the_accuser

11-20-10, 05:50

Thanks for all the compliments! I have noticed that the 16" barrel seems to cool down faster after dimpling than when it was in it's original form. I haven't noticed any accuracy changes since dimpling but I don't do any mag dumps nor do I have a full auto lower to try. I hope to take a carbine course next year using the 16" barrel so I guess I will see then if there are any negative affects.

bubba04

11-20-10, 08:30

That does look real nice! What was their turn around time?

the_accuser

11-20-10, 14:32

That does look real nice! What was their turn around time?

I think it was about a week door to door. I know each barrel was gone less than two weeks for sure.

Brahmzy

11-20-10, 18:39

I'm sending out 3 of my Noveske barrels for KAC dimples.
I'll post a detailed thread with before and after weights, pics and range reports.
I'm sending:
10.5 SS
14.5 SS
16 SS 7.62

Big $$$. Ugh.

orionz06

11-20-10, 18:44

God damn that looks good.

Doesn't dimpling the barrel help with heating? Something about more surface space?

Without doing the math, I think it capable of having a greater surface area over fluting. Not sure if it works out that way in practice though, it may just be more looks and less function.

9DivDoc

11-20-10, 20:50

mcmillanman5

11-20-10, 21:12

Here are a few pics of some that I have had done. The 12.5" dropped ~5oz, not sure on the 18". I would bet that contouring would shave more weight.

Noveske 12.5"

http://i207.photobucket.com/albums/bb80/mcmillanman5/103_0452.jpg

http://i207.photobucket.com/albums/bb80/mcmillanman5/103_0449.jpg

Noveske 18"

http://i207.photobucket.com/albums/bb80/mcmillanman5/DSC08951-1.jpg

http://i207.photobucket.com/albums/bb80/mcmillanman5/DSC08963.jpg

Bolt_Overide

11-20-10, 22:40

Anyone got a rough idea of the amount of weight you can save on the average 16 inch barrel with dimpling?

Luke_Y

11-21-10, 11:47

I'm sending out 3 of my Noveske barrels for KAC dimples.
I'll post a detailed thread with before and after weights, pics and range reports.
I'm sending:
10.5 SS
14.5 SS
16 SS 7.62

Big $$$. Ugh.

Who are you sending them to? ADCO or someone else?

blacklabel66

11-21-10, 12:35

Very nice, who did the work on those barrels? I'm interested in getting mine done in that same pattern.

Here are a few pics of some that I have had done. The 12.5" dropped ~5oz, not sure on the 18". I would bet that contouring would shave more weight.

Noveske 12.5"

http://i207.photobucket.com/albums/bb80/mcmillanman5/103_0452.jpg

http://i207.photobucket.com/albums/bb80/mcmillanman5/103_0449.jpg

Noveske 18"

http://i207.photobucket.com/albums/bb80/mcmillanman5/DSC08951-1.jpg

http://i207.photobucket.com/albums/bb80/mcmillanman5/DSC08963.jpg

mbogo

11-21-10, 12:45

How much does it cost per barrel or inch?

mbogo

cj5_dude

11-21-10, 13:03

ADCO Firearms Webpage (http://www.adcofirearms.com/shopservices/shop_.cfm?code=21)

According to their website it's $115 forward of the FSB and $125 under the handguard. They also do fluting.

mbogo

11-21-10, 13:15

Thank you for the link.

mbogo

Curare

11-21-10, 13:31

McMillan's appear to have been done differently. This spacing and overall quality look fantastic.

.45fmjoe

11-21-10, 16:01

McMillan's appear to have been done differently. This spacing and overall quality look fantastic.

His were probably done by Marvin, the guy who worked for KAC and created that pattern.

ALCOAR

11-21-10, 16:10

His were probably done by Marvin, the guy who worked for KAC and created that pattern.

I agree...his work is simply outstanding. Not that the ADCO is not awesome stuff as well but the whole proprietary KAC pattern is more aesthetically pleasing. I was going to send him a 16" mrp CL a few months back but got sidetracked.

bobslife6826

11-21-10, 16:41

I agree...his work is simply outstanding. Not that the ADCO is not awesome stuff as well but the whole proprietary KAC pattern is more aesthetically pleasing. I was going to send him a 16" mrp CL a few months back but got sidetracked.

Do you have contact info for this guy or anyone else who dose the KAC pattern

ALCOAR

11-21-10, 16:47

^^PM sent^^:)

blacklabel66

11-21-10, 17:35

I'd like his contact info as well, please. :D

.45fmjoe

11-21-10, 17:44

Isn't he at Wilson Combat now? I think that's what I read.

cj5_dude

11-21-10, 17:49

Point out the difference between the KAC and the ADCO dimpling, because I'm really not seeing it.

Belmont31R

11-21-10, 17:53

Point out the difference between the KAC and the ADCO dimpling, because I'm really not seeing it.

ADCO is just done in a straight line. KAC is a golf ball pattern so its a more dense setup. More dimples over the course of doing a barrel.

Luke_Y

11-22-10, 07:51

Somebody post or PM me this outfits info. Thanks.

Spider 6888

11-23-10, 11:53

I WOULD LIKE THE GUYS NAME ALSO.

TurretGunner

11-23-10, 13:16

God damn that looks good.

Doesn't dimpling the barrel help with heating? Something about more surface space?

Heats up quicker and cools quicker. There is a reason F/A belt feds use heavy, nonflutted/dimpled barrels.

Its an absolutley useless process that can adversley effect harmonics and barrel stressing. If saving weight is your goal, just go to a lower/slim contour.

kdcgrohl

11-23-10, 14:59

ADCO dimples:

http://i627.photobucket.com/albums/tt358/kdcgrohl/stuff/IMG_20101025_141632.jpg

koz

11-24-10, 21:57

Heats up quicker and cools quicker. There is a reason F/A belt feds use heavy, nonflutted/dimpled barrels.

Its an absolutley useless process that can adversley effect harmonics and barrel stressing. If saving weight is your goal, just go to a lower/slim contour.

Except the Mk46 mod 1... It's fluted...

jeremy stanke

11-24-10, 22:16

what profile barrels are you guys having dimpled? anyone used a lightweight profile?

ugotbit

11-25-10, 14:06

TurretGunner

11-25-10, 14:11

Except the Mk46 mod 1... It's fluted...

That system was designed to shed weight. Best bud was a mk 48 / 46 gunner in 2nd batt. He did love it like a baby though. I still stand by its a useless process for gear queers.

ALCOAR

11-25-10, 14:49

Trident- Where the hell you been? You are responseable for this creation and I haven't seen you around for you to get credit.

http://i22.photobucket.com/albums/b350/ugotbit/recce005.jpg

http://i22.photobucket.com/albums/b350/ugotbit/recce004.jpg

http://i22.photobucket.com/albums/b350/ugotbit/recce001.jpg

Marvin did my barrel and assembled the upper. The barrel is a Rainier Arms UM 16in.

Damn brother, that is absolutely outstanding....what a beautiful gun that is. That is what happens when you take your time and invest wisely on a build. The proof is in the pudding on Marvin's work above, he works magic on those dimples:)

Great to see you on M4C and now that badass new Recce. Me and the Kiddy site parted ways for good.

Robb Jensen

11-25-10, 14:51

I'm waiting to hear back from Marvin. I want 2-3 barrels done.

ALCOAR

11-25-10, 15:24

ugotbit

11-25-10, 15:52

The most recent pal of mine who got work done on some MRP barrels said that it took several weeks turnaround and be prepared to wait some time. If you don't mind having your barrel/s gone for a month or so than the work is well worth it imho and totally proprietary:cool:

It took some time, but it was worth the wait. Mine was about 6-7 weeks.

It's not for everyone, but it looks cool to me.

Robb Jensen

11-25-10, 16:22

The most recent pal of mine who got work done on some MRP barrels said that it took several weeks turnaround and be prepared to wait some time. If you don't mind having your barrel/s gone for a month or so than the work is well worth it imho and totally proprietary:cool:

I have several guns/uppers I can use for 3gun but I'd love to have my SS410 16" midlength dimpled from the low pro gas block forward. After getting that dimpled I'd like my BCM BFH 14.5" midlength dimpled.

ALCOAR

11-25-10, 16:59

I have several guns/uppers I can use for 3gun but I'd love to have my SS410 16" midlength dimpled from the low pro gas block forward. After getting that dimpled I'd like my BCM BFH 14.5" midlength dimpled.

I really hope you do the SS410 16" and I would love to do all my SS barrels from the GB forward if you see no negative effects on accuracy. That could be a big deal in helping out with balance and weight on a heavier SS barreled rig.

It took some time, but it was worth the wait. Mine was about 6-7 weeks.

It's not for everyone, but it looks cool to me.

Your right its not for everyone as you have to be a man of vision and patience but if you are the rewards are awesome and you end up with a truly one of kind, custom piece like yours is. It really is a sign of a "builder's touch" and seems to make a really custom build "pop". The small things and the attn. to detail usually win me over on top shelf, high dollar builds.

sgtmajor

12-01-10, 13:15

Luke_Y

12-01-10, 16:15

made my noveske recon barrel about 1.9 lighter

I take it you just had it done forward of the GB?

KRAZYKIDDJOE

12-06-10, 11:10

Can someone please PM me Marvin's info? And what a ball park price would be on a 16" SS410 BCM barrel would run me to have dimpled under handguard and in front of gas block?

Thanks
KKJ

devinsdad

12-07-10, 14:43

I receintly had ADCO flute a barrel of mine. Originally I was going for dimples, but since my main goal was to lose weight, I went for the flutes. Also, since this was going under the handguard, I wouldn't be able to enjoy the looks as much.

shootist~

12-07-10, 18:57

For a very light 18" barrel consider the 18" chrome lined Sabre - it comes fluted from the factory. The two I know of locally shoot very well.

One was put together as a long range 3-Gun rifle and preforms very well at distance with 77gr SMKs. It's so-so with cheap WW 55gr reloads, but it's older twin even shoots those well.

These are mid length gas, btw.

Belmont31R

12-07-10, 19:15

DD has now listed an 18" middy CHF lightweight barrel on their site....

royta

12-07-10, 19:25

DD has now listed an 18" middy CHF lightweight barrel on their site....

Where? When you click on "Lightweight" under the Profiles section, it lists four 10.3", four 11.5", four 12.5", eight 14.5", and eight 16" barrels.
http://danieldefense.com/cold-hammer-forged-barrels.html?barrel_profile=41

Belmont31R

12-07-10, 19:31

Where? When you click on "Lightweight" under the Profiles section, it lists four 10.3", four 11.5", four 12.5", eight 14.5", and eight 16" barrels.
http://danieldefense.com/cold-hammer-forged-barrels.html?barrel_profile=41

Actually doesn't look like a true LWT barrel profile as its thicker under the handguards but in front of the FB is a thin profile. You can tell by the step right behind the threads...odd profile...

http://danieldefense.com/cold-hammer-forged-barrels/18-inch-chf-barrels.html

royta

12-07-10, 20:24

Actually doesn't look like a true LWT barrel profile as its thicker under the handguards but in front of the FB is a thin profile. You can tell by the step right behind the threads...odd profile...

http://danieldefense.com/cold-hammer-forged-barrels/18-inch-chf-barrels.html

LOL. That's the Strength 2 Weight profile, and appears to be the heaviest profile they offer. Not exactly what I'd call "Lightweight".

Strength 2 Weight
http://danieldefense.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/1/6/16_s2w_stripped.jpg

M4
http://danieldefense.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/d/d/dd-9067_16_m4_1.jpg

Lightweight
http://danieldefense.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/d/d/dd-9089_16_mid_lw.jpg

Government
http://danieldefense.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/d/d/dd-9081_16_midlength_govt.jpg

These are pictures of 16" barrels and all but the M4 profile are mid-length gas systems.

ETA - I don't know, I guess I could be wrong on the S2W being the heaviest profile of the four. Of all four profiles, the S2W is the heaviest at the chamber. There isn't a lot of material removed in any one section of the barrel like you see on the other three profiles. There is just a nice straight taper from end to end, which is why I think it's the heaviest of the four profiles.

9DivDoc

12-07-10, 21:31

Can someone please PM me Marvin's info? And what a ball park price would be on a 16" SS410 BCM barrel would run me to have dimpled under handguard and in front of gas block?

Thanks
KKJ

Marvin Pitts nefariousarms@live.com

AEuropa

12-20-10, 09:52

kdcgrohl

12-27-10, 13:04

WOA 16" SS 6.8SPC barrel just back from Marvin.
http://i627.photobucket.com/albums/tt358/kdcgrohl/stuff/IMG_20101227_140037.jpg

BCM BFH dimpled by ADCO for comparison.
http://i627.photobucket.com/albums/tt358/kdcgrohl/firearms/IMG_20101224_143450.jpg

Brahmzy

12-27-10, 13:12

Got my 10.5 Noveske barrel back from Marvin a week or so ago. Holy cow he does amazing work. And holy cow this SBR shoots flat and smooth!
He's got my 14.5 Noveske Afghan barrel now and I'll be sending my 16" 7.62 Noveske barrel to him in a week after it's done hunting(hopefully successfully.) :)

http://img690.imageshack.us/img690/512/sbr01s.jpg (http://img690.imageshack.us/i/sbr01s.jpg/)
http://img10.imageshack.us/img10/5454/sbr02s.jpg (http://img10.imageshack.us/i/sbr02s.jpg/)
http://img155.imageshack.us/img155/2798/sbr03s.jpg (http://img155.imageshack.us/i/sbr03s.jpg/)
http://img26.imageshack.us/img26/4346/sbr04s.jpg (http://img26.imageshack.us/i/sbr04s.jpg/)
http://img191.imageshack.us/img191/1175/sbr05s.jpg (http://img191.imageshack.us/i/sbr05s.jpg/)
http://img707.imageshack.us/img707/3637/sbr06s.jpg (http://img707.imageshack.us/i/sbr06s.jpg/)
http://img151.imageshack.us/img151/4093/sbr07s.jpg (http://img151.imageshack.us/i/sbr07s.jpg/)
http://img441.imageshack.us/img441/7453/sbr08s.jpg (http://img441.imageshack.us/i/sbr08s.jpg/)

bubba04

12-27-10, 14:31

I need to decide if I am going to get a 18" SS rifle length gas system or 16" mid length SS barrel to do this too....

Has anyone seen any effects with accuracy?

Brahmzy

12-27-10, 15:30

I need to decide if I am going to get a 18" SS rifle length gas system or 16" mid length SS barrel to do this too....

Has anyone seen any effects with accuracy?

If you're going 18" then get Noveske's brand new lightweight Rogue Hunter barrel 32oz! No need to lighten it. :cool:

royta

12-27-10, 16:01

If you're going 18" then get Noveske's brand new lightweight Rogue Hunter barrel 32oz! No need to lighten it. :cool:

The Rogue Hunter upper uses the standard 38 ounce SPR barrel. They offer an NST upper which uses the 32 ounce Lightweight barrel, or you can buy the barrel separate.

Sent from my Droid using Tapatalk

kdcgrohl

12-28-10, 07:28

For those wondering about weight, the quoted weight of my barrel alone from WOA was 2lb1oz.
The weight after Marvin did his work, INCLUDING a Vltor gas block with set screws & taper pin, Vltor VIS barrel nut and GunKote is 1lb13.9oz

tylerw02

12-28-10, 09:13

Brahmzy

12-28-10, 09:34

Dimpling and fluting barrels is more hype and expense than practicality. On precision rifles, some of the most respected gunsmiths are firmly against it. If you need to shed weight, do it another way.

So Noveske aren't respected gunsmiths?
And who says these all of these are precision rifles?
On a varmit or "precision" rig, no, I would stick with a fat/heavy barrel because it's sitting on a bench or bipod.

My three rifles I'm having dimpled are shouldered / carried rifles.

There's no "hype" about dropping weight. Being able to keep my Noveske med. contour without the drastic affects of recontouring the barrels is a huge plus. I would say Marvin's dimpling is the LEAST intrusive post-production method of dropping barrel weight.
Being able to swing easier and get back on target for followup shots is a far better tradeoff than losing a 1/4MOA of precision - IF you lose any precision. Show me proof anything is lost. Many ACTUAL shooters have noticed ZERO negative affects from fluting. Some of these people include Noveske's shooting team members.

Careful with blanket statements.

tylerw02

12-28-10, 09:53

So Noveske aren't respected gunsmiths?
And who says these all of these are precision rifles?
On a varmit or "precision" rig, no, I would stick with a fat/heavy barrel because it's sitting on a bench or bipod.

My three rifles I'm having dimpled are shouldered / carried rifles.

There's no "hype" about dropping weight. Being able to keep my Noveske med. contour without the drastic affects of recontouring the barrels is a huge plus. I would say Marvin's dimpling is the LEAST intrusive post-production method of dropping barrel weight.
Being able to swing easier and get back on target for followup shots is a far better tradeoff than losing a 1/4MOA of precision - IF you lose any precision. Show me proof anything is lost. Many ACTUAL shooters have noticed ZERO negative affects from fluting. Some of these people include Noveske's shooting team members.

Careful with blanket statements.

Can you not read? I said some of the most respected gunsmiths...

Noveske doesn't make really "precision rifles" either.

You do lose precision. Ask Mike Rescigno of Tactical Operations about it sometime.

I said nothing of it being hype to reduce weight---the hype is using fluting or dimpling to do so.

Back to what I said...if you need to shed weight, do it another way. Go with a lighter contour barrel, use a lighter quad rail, go shorter on the barrel, etc. There are more practical ways than having your barrel fluted. If you want to get one dimpled or fluted, knock yourself out, Bucko.

RiggerGod

12-28-10, 22:01

So anybody dimple a lightweight barrel yet? I just finished a sub 5.5lb blaster for the Mrs. and if I could just find a way to save a little more weight.... A sub 5.0 or 5.25 carbine would be sick!!!

reiswigt

12-28-10, 22:42

Does anyone dimple or flute their barrels in the early stages of production so as to not create any undue stress, thereby reducing weight and not adversely affecting accuracy?

royta

12-29-10, 06:10

Noveske doesn't make really "precision rifles' either.

You do lose precision. Ask Mike Rescigno of Tactical Operations about it sometime.

Back to what I said...if you need to shed weight, do it another way. Go with a lighter contour barrel, use a lighter quad rail, go shorter on the barrel, etc. There are more practical ways than having your barrel fluted.

Serious question here. So, you're saying it would be better to buy a Noveske 32 ounce 18" Lightweight barrel than to buy a Noveske 38 ounce 18" SPR barrel and have Noveske flute it, even though the latter would maintain the overall diameter of the SPR profile?

Sent from my Droid using Tapatalk

tylerw02

12-29-10, 09:19

Brahmzy

12-29-10, 09:46

Serious question here. So, you're saying it would be better to buy a Noveske 32 ounce 18" Lightweight barrel than to buy a Noveske 38 ounce 18" SPR barrel and have Noveske flute it, even though the latter would maintain the overall diameter of the SPR profile?

Sent from my Droid using Tapatalk

I agree with Bucko above, it all depends on your use. If you're wanting a long-range bench/bipod gun, weight shouldn't be a concern - heavy is good. I would not alter a precision barrel in anyway, and I probably wouldn't even put a muzzle device on the end of it if I was shooting for match or strictly paper precision. If you're looking for a working rifle that you're huffing around all over the place and do not need 1/2 MOA accuracy out of, after you've lightened everything else on the gun, then by all means flute it or dimple it.
My 3 rifles I dropped the barrel weight on (dimpled) because I have bought the absolute lightest components on the rest of the rifles and still want to go lighter, BUT I still wanted to maintain the medium contour SS Noveske barrel, not a pencil CL barrel. I still maintain the benefits of the heavier profile and SS accuracy without having a pencil barrel heat up and start walking my shots (another debatable topic.) I never intended these 3 rifles I built to be long range precision weapons.
This is one of the most debated topics, and I've heard people say the craziest things on both extremes. I've also heard that Noveske's lightweight Rogue Hunter 6.8 SS barrels are straight up 1/2 MOA barrels, even at long range, which defies most folks logic. You don't see many lightweight profile SS barrels out there.
All depends on what you're wanting and how far out you're expecting said weapon to reach.
Also, on the subject of reprofiling a barrel, post-production, I think this is just about the most intrusive thing you could do to the metal of a barrel. It changes the entire structure of the metal, causing changes in how it heats up, cools and shoots. I would think the harmonics would change drastically. I would only buy a lightweight profile from the get-go - I don't think I'd have one turned down unless I absolutely didn't care about precision or I absolutely had no other choice. That said, there are folks that have had barrels turned/re-profiled and swear by it.
Again, there's not a whole lot of scientific proof that is floating around about all of this. I know a lot of the high-end manufacturers have done the math and the hard work here. Why would KAC dimple their barrels on their $5,000 EMC SR-25's to drop the weight if they weren't concerned with accuracy? Those things are friggin' tack drivers. How is LaRue able to get the insane 1/4-1/3MOA out of his guns using the methods he does?

I have yet to see a thread where somebody has done thorough, extensive before and after shot comparisons in regards to the different barrel lightening methods. For the most part, it's all people regurgitating what they've heard. I was shooting about 1MOA (I'm not the best shooter by any means) out of my dimpled 10.5 at 25 yards with FGGM's. I had not had the chance to do a before comparison as this was a new build and a new barrel. And to be honest, it's not really needed with an SBR. I DO know what I was shooting with my Afghan barrel before I sent it out and will know right away if the dimpling had any negative effects on the barrel's accuracy.

montrala

12-30-10, 13:03

Many gunsmiths claim that fluting a rifle barrel after the rifling process introduces stress and can cause loose spots in a bore, leading to a reduction in accuracy.

It would be interesting to know how this apply to CHF barrels. In this case production technology seem to make different material structure of barrel. But it evades me if dimpling or fluting of ready barrel would lead to better or worse results than on traditional barrel.

I actually can not see possibility to dimple or flute CHF barrel before making finished bore, as hammering process would destroy fluting/dimpling.

Can someone put some light on this? I have feel some itching to do something terrible to my HK MR223 16.5" heavy profile CHF barrel ;)

mcmillanman5

12-30-10, 19:38

Can you not read? I said some of the most respected gunsmiths...

Noveske doesn't make really "precision rifles" either.

.

That is not exactly true. Some of the best shooting rifles I have seen were built by the good folks at Novseke.

Here is a rifle that I had John build for my Dad. This rifle will literally shoot one hole groups with a variety of ammo. This has a fluted barrel as do several others I have used that all shot well.

http://i120.photobucket.com/albums/o189/hs338lapua/betterdadsgun.jpg
http://i120.photobucket.com/albums/o189/hs338lapua/DSC07149.jpg

I am no metallurgist or machinist/gunsmith and I am not trying to be argumentative, but I have personally used or owned several rifles that have been fluted or dimpled with no adverse effects.

Research it yourself and you may come to a different conclusion, but this is the one I've reached.

I think that you hit it on the head with this statement.

sgtmajor

01-20-11, 00:17

I'll throw my 2 cents in here, the original reason kac came up with "dimpling" a barrel this way was to reduce heat by creating more surface area. The weight lose is just an added bonus.

decodeddiesel

01-28-11, 15:40

9DivDoc

01-28-11, 20:48

I agree with Bucko above, it all depends on your use. If you're wanting a long-range bench/bipod gun, weight shouldn't be a concern - heavy is good. I would not alter a precision barrel in anyway, and I probably wouldn't even put a muzzle device on the end of it if I was shooting for match or strictly paper precision. If you're looking for a working rifle that you're huffing around all over the place and do not need 1/2 MOA accuracy out of, after you've lightened everything else on the gun, then by all means flute it or dimple it.
My 3 rifles I dropped the barrel weight on (dimpled) because I have bought the absolute lightest components on the rest of the rifles and still want to go lighter, BUT I still wanted to maintain the medium contour SS Noveske barrel, not a pencil CL barrel. I still maintain the benefits of the heavier profile and SS accuracy without having a pencil barrel heat up and start walking my shots (another debatable topic.) I never intended these 3 rifles I built to be long range precision weapons.
This is one of the most debated topics, and I've heard people say the craziest things on both extremes. I've also heard that Noveske's lightweight Rogue Hunter 6.8 SS barrels are straight up 1/2 MOA barrels, even at long range, which defies most folks logic. You don't see many lightweight profile SS barrels out there.
All depends on what you're wanting and how far out you're expecting said weapon to reach.
Also, on the subject of reprofiling a barrel, post-production, I think this is just about the most intrusive thing you could do to the metal of a barrel. It changes the entire structure of the metal, causing changes in how it heats up, cools and shoots. I would think the harmonics would change drastically. I would only buy a lightweight profile from the get-go - I don't think I'd have one turned down unless I absolutely didn't care about precision or I absolutely had no other choice. That said, there are folks that have had barrels turned/re-profiled and swear by it.
Again, there's not a whole lot of scientific proof that is floating around about all of this. I know a lot of the high-end manufacturers have done the math and the hard work here. Why would KAC dimple their barrels on their $5,000 EMC SR-25's to drop the weight if they weren't concerned with accuracy? Those things are friggin' tack drivers. How is LaRue able to get the insane 1/4-1/3MOA out of his guns using the methods he does?

I have yet to see a thread where somebody has done thorough, extensive before and after shot comparisons in regards to the different barrel lightening methods. For the most part, it's all people regurgitating what they've heard. I was shooting about 1MOA (I'm not the best shooter by any means) out of my dimpled 10.5 at 25 yards with FGGM's. I had not had the chance to do a before comparison as this was a new build and a new barrel. And to be honest, it's not really needed with an SBR. I DO know what I was shooting with my Afghan barrel before I sent it out and will know right away if the dimpling had any negative effects on the barrel's accuracy.

How many weapons assemblers/manufacturers contour their barrels
prior to drilling out the bore and rifling it?

Don't contour their barrels after the bores are drilled and the rifling created?...

Randal of AR15 Barrels once stated that he got good accuracy improvements in barrels by re-contouring them..because after
he was done the bores were more concentric to the surrounding metal.

If that is the case then a top notch machinist could actually make a mediocre barrel into a better barrel...all things being equal..

That being said and having barrels fluted,dimpled and re-contoured
I find the re-contoured is both lighter and the better bang for the buck.

The trick is making sure a quality machinist does the work...and for that
most likely you will have to pay a bit more than you will to the neighborhood blacksmith...

imo

InfiniteGrim

01-29-11, 14:43

I would think dimpling your barrel would benefit looks more then weight. You would be far better off with a pencil barrel.

TurretGunner

01-30-11, 15:56

I'll throw my 2 cents in here, the original reason kac came up with "dimpling" a barrel this way was to reduce heat by creating more surface area. The weight lose is just an added bonus.

It also heats up at the same rate it cools. Its a moot point.Dimpling is a Gear queer , useless process. If you want lighter, get a smaller contour. Who gives a shit what KAC does. I would hardly call the SR-25 the standard. I would take a Gap build .308 AR any day of the week before a KAC.

Belmont31R

01-30-11, 16:18

It also heats up at the same rate it cools. Its a moot point.Dimpling is a Gear queer , useless process. If you want lighter, get a smaller contour. Who gives a shit what KAC does. I would hardly call the SR-25 the standard. I would take a Gap build .308 AR any day of the week before a KAC.

Lighter barrels heat up faster, and can have issues with POI shift from cold to hot.

The idea is to have a more rigid barrel than pencil that still cools faster than a heavy barrel with no dimpling or fluting. Thats a more ideal setup than just throwing a pencil barrel on there if you want to maintain accuracy for a longer duration when firing. If you had a barrel that weighs the same as an EMC barrel side by side it would be stiffer but not have as much surface area so it would cool down slower.

As far as GAP vs. Knight's thats preference more than anything. I really like the URX series of rails, and the new GAP receiver raises the top rail height up way too much to me. Same reason I haven't gotten a OBR yet. I don't want to have to have some cheek rest contraption to get a proper height. Then where GAP doesn't have a rail section is right where Id normally place a Surefire pad. So for me the EMC does what I want a gun to do a lot better. Id also have to shoot both, and see what they feel like weight wise and balance wise. The EMC is really well balanced, is one of the lighter 308's out there, and with the gas system setup is really smooth in operation. I owned an MWS first, and even though it weighed more it recoiled quite a bit harder. So hard follow up shots were quite a bit slower, and it wasn't all that enjoyable to shoot for 200-300 rounds.

TurretGunner

01-30-11, 17:13

Lighter barrels heat up faster, and can have issues with POI shift from cold to hot.

The idea is to have a more rigid barrel than pencil that still cools faster than a heavy barrel with no dimpling or fluting. Thats a more ideal setup than just throwing a pencil barrel on there if you want to maintain accuracy for a longer duration when firing. If you had a barrel that weighs the same as an EMC barrel side by side it would be stiffer but not have as much surface area so it would cool down slower.

As far as GAP vs. Knight's thats preference more than anything. I really like the URX series of rails, and the new GAP receiver raises the top rail height up way too much to me. Same reason I haven't gotten a OBR yet. I don't want to have to have some cheek rest contraption to get a proper height. Then where GAP doesn't have a rail section is right where Id normally place a Surefire pad. So for me the EMC does what I want a gun to do a lot better. Id also have to shoot both, and see what they feel like weight wise and balance wise. The EMC is really well balanced, is one of the lighter 308's out there, and with the gas system setup is really smooth in operation. I owned an MWS first, and even though it weighed more it recoiled quite a bit harder. So hard follow up shots were quite a bit slower, and it wasn't all that enjoyable to shoot for 200-300 rounds.

This is pure bullshit. I know the "theory" behind fluting/dimpling and it has been proven to be pure bullshit. Its athstetic at best. The idea of a more rigid barrel is also BS. What scientific evidence do you have to support this? Its a gear queer product for the US consumer. It is not used in hardly any military weapons.

A barrel that is fluted or dimpled may cool down faster, but it will heat up equally fast. Its physics. Learn it. On top of that it can mess with the harmonics of the barrel. You really want to take a primo blank, have it chambered/reamed and then start cutting chunks out of it?

Stop trying to defend poor choices made by people who did not do the research or listen to SME before they paid 2-3-400 or whatever it cost to hack up their barrel. Admit that it is for gear queers and makes your 3 thousand dollar safe queen look cool. I was not going to post again in this thread but posts like this are to easy of targets.

Or do yourself a favor and go over to snipershide and tell them about how much better your dimpled barrel is then theirs is. There are more than a few people here and there who will tell you the same. Also dont expect IP and people who work for certain companies who have financial/legal stake to come out and blast their products.

Belmont31R

01-30-11, 17:44

This is pure bullshit. I know the "theory" behind fluting/dimpling and it has been proven to be pure bullshit. Its athstetic at best. The idea of a more rigid barrel is also BS. What scientific evidence do you have to support this? Its a gear queer product for the US consumer. It is not used in hardly any military weapons.

A barrel that is fluted or dimpled may cool down faster, but it will heat up equally fast. Its physics. Learn it. On top of that it can mess with the harmonics of the barrel. You really want to take a primo blank, have it chambered/reamed and then start cutting chunks out of it?

Stop trying to defend poor choices made by people who did not do the research or listen to SME before they paid 2-3-400 or whatever it cost to hack up their barrel. Admit that it is for gear queers and makes your 3 thousand dollar safe queen look cool. I was not going to post again in this thread but posts like this are to easy of targets.

Or do yourself a favor and go over to snipershide and tell them about how much better your dimpled barrel is then theirs is. There are more than a few people here and there who will tell you the same. Also dont expect IP and people who work for certain companies who have financial/legal stake to come out and blast their products.

You need to tone down on the attitude.

Yes it heats up faster than non-dimpling because theres less mass. I know that. Its not going to heat up as fast a pencil barrel which is what you are pushing if someone wants to cut weight.

Wheres you're evidence? You want to come on here and talk down to people and act like an ass while you haven't shared anything to back up your claims.

Go talk to snipershide? Why don't you go call Krieger and tell them they're wrong on barrel fluting? http://www.kriegerbarrels.com/Fluting-c1246-wp3392.htm

Why don't you also call Lilja tomorrow, and tell them they are wrong....

Q: Does fluting cause stress in a barrel?

A: We've been asked if machining flutes into a rifle barrel causes stress in the steel. The short answer is no, it does not. There are some operations in the manufacture of a rifle barrel that can cause stress to develop in the steel, but fluting is not one of them. To the contrary, fluting can and will relieve stress if it is already present. The same is true of any outside machining work performed on a barrel.

The type of stress that can exist in a barrel is called compressive stress. Under normal conditions the stress could form from two processes. When steel is manufactured, the round shape is formed through a rolling operation in the steel mill. This forming can be performed either hot or cold. Cold rolling generates a great deal of internal stress in the steel. Usually, with steel used for rifle barrels, this stress is relieved by heating the steel to just below its transformation or critical temperature. We have the steel mill that makes our steel do this as their very last operation, ensuring us that the steel is stress free when we receive it.

Secondly, stress can be formed in a rifle barrel during a cold forming operation, such as button rifling. Since no material is removed from the barrel when the rifling is formed, rather it is displaced, it causes compressive stress in the steel. If this stress is not removed, through a heat treating operation, it will remain in the steel where it can cause other problems. Any subsequent machining operations, such as turning the outside diameter of the barrel, will allow some of those stresses to come out. The result can be an opening of the inside diameter of the barrel, more so towards the muzzle where more material is machined away. It can and probably will also cause the barrel to warp. And if these aren't enough, the temporary heating and cooling of the barrel that occurs during normal firing will also let the stress come out by warping the barrel. Poor accuracy is the result.

Although a barrel would not normally be welded on, this can also cause stresses to form in steel. At times though, gunsmiths will heat barrels to sweat-on barrel bands and sites. Too much heat can cause some problems as well.

But, the fact remains that normal machining operations, such as outside turning, fluting, drilling and tapping site holes, etc. do not cause or introduce stress. They can and do allow residual stresses to come out of the steel though.

We flute about 50 rifle barrels per month and have never had a problem with our barrels related to fluting.

http://www.riflebarrels.com/faq_lilja_rifle_barrels.htm#stress

With the stiffness if you read what I wrote you would understand what I was saying which is NOT that dimpling or flutting makes a barrel stiffer. It doesn't. What I said its a dimpled barrel like what an EMC has is going to be stiffer than a pencil barrel.

As to causing stress in the barrel Id guess you would have to go argue that point with Krieger and Lilja. You can all up their engineering people and tell them how much more you know about barrel making than them. Call GA Precision, too, since they offer barrel fluting. Tell them they are screwing up barrels offering that service.

Here is Kriegers # 262-628-8558

Lilja # (406) 826-3084

GA Precision # (816) 221-1844

Let us know the results.

Oh and the Army SDM-R is a fluted barrel.

Belmont31R

01-30-11, 17:52

Oh since you wanted to bring up Sniper's Hide read this thread: http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=2275715

They are saying the same thing I am....:rolleyes:

Brahmzy

01-30-11, 22:46

Great posts Belmont.

That is all right in line with what I've heard from various horse's mouths and well, just what makes sense. I think ol Turret Gunner must've used "gear queer" 3 or 4 times - he must like that term or something.

Anyway, to be honest I think the dimpling looks a little goofy, but I was able to get 6oz shaved off of my 14.5 Afghan and still maintain it's medium profile. That's close to a half pound and I can sure tell a difference pointing it! Its like a brand new rifle.
Yet, I still have none of the potential drawbacks of a pencil barrel. The thing shoots the exact same, slow or fast fire than it did before as far as accuracy, heatup, cooldown, etc.
I know for a fact that dimpling has made an amazing difference on how my ARs handle (I've had Marvin do 3 barrels now) and it hasn't diminished anything. I guess it must be just for Gear Queers! :D

Not sure why so much emotion comes out on this subject, but it does, haha.

ALCOAR

01-30-11, 22:54

Brahmzy

01-31-11, 07:42

I would say so much emotion gets involved on this topic because 9.5/10 people who dimple their barrels did it purely for aesthetics and rather than just being honest they spin up all these ways that dimpling not only doesn't hurt a barrel but it some hows makes it better.

One way or the other, if your position is that it makes a noticeable positive difference, or that it makes a noticeable negative difference, your dealing in mind pondering science way to much and your conclusions are more than likely tied to your own personal beliefs rather than any scientific piece of evidence or proof.

Um, how about putting my freaking rifle on a scale for scientific proof? Or is that in my mind? How about doing before and after paper punching and getting the exact same groupings? Is that in my mind? Granted I'm not the best paper puncher (like Molon or someone) but I know my capabilities behind the trigger of this particular rifle, and that didn't change from a benchrest perspective.
I don't think anybody's "spinning up" anything.

tylerw02

01-31-11, 08:38

Some companies LOVE barrel fluting. There is good money in fluting.

But fact of the matter is, for everybody you find that is "pro" fluting, you're also going to find those against it.

So does this count as "proof"?

What about "fluting" a barrel?
Fluting is a service we neither offer nor recommend. If you have a Shilen barrel fluted, the warranty is void. Fluting a barrel can induce unrecoverable stresses that will encourage warping when heated and can also swell the bore dimensions, causing loose spots in the bore. A solid (un-fluted) barrel is more rigid than a fluted barrel of equal diameter. A fluted barrel is more rigid than a solid barrel of equal weight. All rifle barrels flex when fired. Accuracy requires that they simply flex the same and return the same each time they are fired, hence the requirement for a pillar bedded action and free floating barrel. The unrecoverable stresses that fluting can induce will cause the barrel to flex differently or not return from the flexing without cooling down a major amount. This is usually longer than a shooter has to wait for the next shot. The claim of the flutes helping to wick heat away faster is true, but the benefit of the flutes is not recognizable in this regard until the barrel is already too hot.
Back to top.

Or why not talk to Mike? He GUARANTEES 1/4 MOA with factory ammunition from his rifles. Ask him what he has to say about fluting.

Tactical Operations, Inc.
433 North Camden Dr. 4th Fl. #239
Beverly Hills, Ca 90210
Phone 310 275-8797
Fax 323 933-3521
info@tacticaloperations.com

Belmont31R

01-31-11, 11:52

Its my understanding there can be some negative reactions in some barrels to fluting...particularly barrels that were button rifled and then fluted. Button rifling basically smashes the metal up into the rest of the barrel to create the lands and grooves. That creates stress just like hammer forging does. If the barrel is not properly stress relieved, and then its fluted you get the weak/soft spots.

It doesn't appear to negatively affect many manufacturers...so to me it seems more like a process issue rather than fluting causes problems. If a barrel wasn't properly stress relieved then cutting away material reveals the stresses already there. It doesn't cause stress. If someone says removing material via cutting introduces stress than how do they even profile the barrel, thread the muzzle for a muzzle device or cut the crown, ect? A barrel goes through a lot of cutting. I have a hard time believing all that cutting doesn't introduce stress but dimpling or fluting does? That doesn't make any sense.

There are a lot of things company's do to make money. Doesn't mean they are selling snake oil. Its obviously physics that more surface areas means more rapid cooling. If you take two barrels of the same weight but different OD the one with the bigger OD is going to be more rigid.

Im sure some companies have had issues with it, but again, I think thats more of an issue with the process they used than there being a negative. People may also see taking an issue with having one barrel, cutting flutes, and then seeing a reduction in accuracy because you are weakening the barrel. Thats not the right way to look at it. The way to look at it is saying I want a 3lb barrel and make it as strong as possible. A 3lb barrel that was fluted or dimpled is going to be stronger than a 3lb barrel that is just a straight cut. If you want to take a 4lb barrel, and cut flutes in it bring the weight down to 3lbs then its not going to be as strong as a 4lb barrel left alone.

There are a lot of top notch companies out there making and using fluted barrels. Accuracy International is one of them, and they make some of the most premier military sniping rifles in the world. If you look at FN they make rifles with a 1/2MOA guarantee that are both fluted and hammer forged...two process which supposedly can introduce the most stress. So I think its how the barrel is treated and made rather that blanket saying doing X is going to be detrimental no matter what. By the logic of saying cutting flutes causes stress, again, how can you make any other cuts and not introduce stress as well?

I emailed Shilen with some questions. Ill post their response if/when I get one.

Some companies LOVE barrel fluting. There is good money in fluting.

But fact of the matter is, for everybody you find that is "pro" fluting, you're also going to find those against it.

So does this count as "proof"?

Or why not talk to Mike? He GUARANTEES 1/4 MOA with factory ammunition from his rifles. Ask him what he has to say about fluting.

Tactical Operations, Inc.
433 North Camden Dr. 4th Fl. #239
Beverly Hills, Ca 90210
Phone 310 275-8797
Fax 323 933-3521
info@tacticaloperations.com

tylerw02

01-31-11, 11:58

Belmont31R

01-31-11, 12:14

Yet you've posted more hearsay, rather than any form of scientific evidence.

Fact of the matter is the only thing fluting does is remain expensive and reduce weight by a small margin.

As a fluting barrel with a greater OD is more rigid than a smaller profile barrel of the same weight, a non-fluted barrel with the same diameter is more rigid than than the fluted barrel.

Fluting is not some kind of miracle...and you concede that fluting improperly is detrimental, you'll find few companies flute the "right" way.

I said the same thing as you, and Im posting hearsay?

If you do anything wrong its possibly going to cause an issue. That doesn't mean fluting is inherently "bad". Using examples of something being done improperly as suggesting all examples no matter if done properly or not isn't exactly sound logic.

Im not debating the value of spending money to get a fluted barrel or buying a gun with a fluted barrel. All Im discussing is the physical value of doing such thing. I don't really care if someone thinks its worth it or not. Value is in the eye of the beholder.

I never said fluting is a miracle. Its simply a process that can yield certain results in a hunk of metal...such as making a stronger barrel of the same weight as a barrel that was not fluted. Like an I-Beam is stronger than just a tube of metal and has more surface area. If you don't think the process is worth the cost then thats up to you to decide. Doesn't take away from the benefits it can offer. Obviously quite a few top notch companies see the benefit in doing it.

orionz06

01-31-11, 12:19

Like an I-Beam is stronger than just a tube of metal and has more surface area.

That is WAAAY too general. What was said above by Tyler was pretty accurate.

Belmont31R

01-31-11, 12:25

That is WAAAY too general. What was said above by Tyler was pretty accurate.

Which is pretty much the same thing I have been saying.

AEuropa

01-31-11, 23:48

sniperfrog

02-01-11, 12:49

Bill Sheehan set a 1000 yard benchrest world record with a barrel that he had fluted after he had already used it for half a season.

ADCO told me that fluting an 18" SPR barrel under the handguards would remove about 5 ounces.

mbogo

02-01-11, 12:54

Barrels are 'individuals'. Dimple/flute 1000 barrels; accuracy-wise, some will be adversely affected, some will benefit, others will be unaffected.

If the weight savings are worth the risk of decreased accuracy, go for it.

mbogo

Belmont31R

02-01-11, 13:18

I'd just like to point out that NO ONE has posted any actual data to support their position.

It cools faster? Ok, show me the numbers.
It causes stress? Ok, show me actual, real-world side effects that adversely affect accuracy, durability, or reliability.
It makes a barrel more stiff? Ok, show me the difference in deflection.

I'm all for hyperbolic arguments...they are what make the internet fun. But unless there's actual data being thrown around, then this is all merely conjecture and people are getting really heated over nothing.

- Alex

Type in google radiant heat transfer formulas. They take into account surface area in the calculation.

Fluting and dimpling increase the surface area therefore the rate of heat transfer to the atmosphere is going to increase.

Its the same concept as fins in a radiator (why they are called radiators actually). The greatly increased surface area in a radiator fin assembly transfers heat out of the solid much more quickly than just having a solid sheet of metal radiating heat out. There are all kinds of examples of objects designed to shed heat quickly through radiation try to get as much surface area as possible.

As far as rigidity read the wiki on how the calculations are made. Im not an engineer or mathematician so Im not going to attempt to measure barrels and test them to give you an exact answer... http://en.wikipedia.org/wiki/Second_moment_of_area

What Im NOT saying is fluting or dimpling strengthens are barrel. That is not true. The only thing doing that does is weaken it, increase heat transfer, and reduce weight. Weight reduction can improve the balance on certain setups.

Where fluting and dimpling comes into play is if you said 'I want to make this gun with a barrel that weighs no more than 2lbs'...a fluted or dimpled barrel that weighs 2lbs is going to be stiffer and have better heat transfer than a barrel that weighs 2lbs with no fluting or dimpling.

Just like a car radiator with fins that weighs 10lbs is going to have better heat transfer rates than a radiator without fins that weighs 10lbs where the heat transfer surfaces are just flat sheets of metal.

SR-47

02-01-11, 15:44

I thought I would post some pictures of a test I did on 2 stainless barrels they are both from the same lot the only difference is that one has been painted black.

in this test I measured the deflection of a stock barrel against a dimpled barrel using 50 pounds of weight hanging from each barrel in a cantilevered barrel fixture that simulates the barrel in a upper receiver

sorry the scale is upside down

stock barrel at rest in test fixture http://i105.photobucket.com/albums/m217/map32968/stockbarrelatzero.jpg

stock barrel with load http://i105.photobucket.com/albums/m217/map32968/stockbarrelwith50ofload.jpg

dimpled barrel at rest in test fixture http://i105.photobucket.com/albums/m217/map32968/dimplebarrelatzero.jpg

dimpled barrel with load http://i105.photobucket.com/albums/m217/map32968/dimplebarrelwith50ofload.jpg

stock barrel weight 2LB .4oz http://i105.photobucket.com/albums/m217/map32968/920g.jpg

dimpled barrels weight 1LB 9.6oz http://i105.photobucket.com/albums/m217/map32968/725g.jpg

thats a difference of 195g or 6.8 oz

here they are side by side http://i105.photobucket.com/albums/m217/map32968/sidebysidebarrels.jpg

I have had no complaints about accuracy
no complaints at all

Marvin

AEuropa

02-01-11, 22:59

Belmont, to be clear, my post was not aimed at you directly. It was just an observation about this thread in general. And you don't need to convince me of the merits of fluting; my Afghan barrel is in the USPS system on it's way back to me from being fluted by Noveske. Based on my own research, I personally believe that it is beneficial (depending on the intended use of the rifle), however I try to steer clear of making absolute statements regarding a subject that I have not personally tested or, at a minimum, seen test results about.

Marvin, thanks for the data. I would be interested in seeing a similar test with 2 barrels of equal weight, one fluted/dimpled and one with a lightweight contour, to see what the results would be. That seems to be the primary argument when it comes to stiffness.

- Alex

Robb Jensen

02-02-11, 06:13

Marvin dimpled my BCM SS410 from the gas block forward. I think it turned out great. I didn't have the midsection dimpled because I had it turned down to .650" by WAR Rifles a while back. I think the next one I'll have done is my Colt 10" SBR barrel.

http://img.photobucket.com/albums/v408/gotm4/dimpledbarrel.jpg

SR-47

02-02-11, 10:22

Marvin, thanks for the data. I would be interested in seeing a similar test with 2 barrels of equal weight, one fluted/dimpled and one with a lightweight contour, to see what the results would be. That seems to be the primary argument when it comes to stiffness.

- Alex

If I were to remove the same weight of material from all the barrels the dimpled barrel will give the best results it will be more rigid than the lighter contour barrel and have more hoop strength than the fluted barrel and I would argue that it has the potential to be more accurate

Evil Bert

02-09-11, 12:05

@Marvin

I am confused by those images. The dimpled with load appears to flex or be less rigid than the non-dimpled barrel. Am I understanding the images? Can someone please explain?

orionz06

02-09-11, 12:06

@Marvin

I am confused by those images. The dimpled with load appears to flex or be less rigid than the non-dimpled barrel. Am I understanding the images? Can someone please explain?

The dimpled barrel deflects more than the non dimpled barrel.

Brahmzy

02-09-11, 13:07

Good grief folks, this isn't rocket science.

decodeddiesel

02-09-11, 13:20

Good grief folks, this isn't rocket science.

No, but it is science of materials.

Evil Bert

02-09-11, 19:29

The dimpled barrel deflects more than the non dimpled barrel.

That is what I thought, but there are people and gunsmiths/mfrs that claim it increases accuracy, but as I understand it, deflection decreases accuracy. These pictures support that with the dimpling.

montrala

02-10-11, 04:14

That is what I thought, but there are people and gunsmiths/mfrs that claim it increases accuracy, but as I understand it, deflection decreases accuracy. These pictures support that with the dimpling.

There is one picture missing. One with barrel that is not dimpled but has some weight like dimpled. Because dimpled or fluted barrel are expected to be stiffer and more accurate that plain barrels of same length and mass, not same length and diameter.

Evil Bert

02-10-11, 06:31

There is one picture missing. One with barrel that is not dimpled but has some weight like dimpled. Because dimpled or fluted barrel are expected to be stiffer and more accurate that plain barrels of same length and mass, not same length and diameter.

okay that makes sense. But I think the pics were a little deceiving to say the least. But good pics none the less. This thread has been very informative.

Brahmzy

02-10-11, 09:57

okay that makes sense. But I think the pics were a little deceiving to say the least. But good pics none the less. This thread has been very informative.

Deceiving?!?! WTF? Kudos to Marvin for showing the after effects of his work - there's some real proof for us. Nothing deceiving about it - try informative and honest. Nothing like hanging 50 freaking pounds off of a barrel. That is a lot of weight.
I'm REALLY hoping I get my 7.62 N6 barrel back from him this week. Today would be perfect - got the day off! :D And my TROY TRX-E 308 rail is in the mail - between the two, I almost shaved an entire pound off the front of my rifle.

Evil Bert

02-10-11, 12:01

Maybe deceiving was a poor choice of words as it implies misleading. What I mean to say was confusing in the sense the same barrel weights were not compared as dimpled vs. un-dimpled with respect to rigidity.

redfernsoljah

03-13-11, 20:40

http://gallery.me.com/redfernsoljah/100427/DSCN0073/web.jpg?ver=13000628220001

MistWolf

03-13-11, 22:29

It's not mis-leading at all if the concept is understood-

Two barrels of the same mass, length, chamber and bore; one is dimpled, the other smooth.
Dimpled barrel will have
-Larger outside diameter
-Greater surface area
-Greater stiffness due to larger diameter and mechanical advantage from shape.

Two barrels of the same diameter, length, chamber and bore; one is dimpled, the other smooth.
Smooth barrel will have
-Greater mass
-Less surface area
-Greater stiffness

If you want a good example of how this works, try the following experiment-

Take a flat sheet of paper and see how well it resists bending. Then, roll it into a single roll with an internal diameter of say .25". It's stiffer than a flat sheet. Now, take that same sheet and cut it into seven equal strips lengthwise. Roll each into a tube with a .25" inside diameter and place six tubes around the seventh. Although the assembly is the same length and weight, it's outside diameter, surface area and stiffness is greater. (Assume the paper sticks to itself so we aren't arguing about glue adding mass)

ZRH

03-14-11, 06:58

MistWolf

03-14-11, 14:05

I understood everything perfectly until I read your example :p

It did remind me of something though: If one could somehow bind a material to the outside of a dimpled surface (or even a waffled one, reuleaux drill bits) you could make a stress skin/torsion box that actually would be as resistant to flex as a solid mass of the equivalent diameter.

I suppose my example (you're talking about my example using paper for tubes, right?) would have been better with an illustration. It also would have been easier to visualize if I'd been talking about fluting.

Each flute cut into the material acts in a similar fashion to a tube in my above example.

You're right about making "stress skin/torsion box". Honeycomb panels are light weight and very stiff