Anyone lighten the barrel on a MWS?

[jrhtx]

I am getting OLD (bitch) and want something a little lighter for hogs or whatever.

I have a spare MWS upper and am thinking about something a bit lighter. Has anyone had a MWS barrel (16" chrome) dimpled or fluted?

Who did it and how does it shoot? Any regrets?

Thanks

 

[epaultmbt]

I had ADCO cut mine to 13.5" (16" with pinned SureFire break) and .750. I haven't noticed any difference in accuracy. No regrets it works great for it's intent. I also have a 18" SS that I use when I want more velocity.

 

[jrhtx]

Did ADCO trim the barrel to .750 behind and in front of the gas block?

I am also looking at cutting and installing a QD FH for suppressor to be 16".

 

[Bravo 1]

Jrhtx

I just read with great interest the new issue of Sniper and it was suggested (can't recall who) that fluting a barrel was very detrimental to accuracy.

When I get home I can look up who wrote it and the reasons why unless someone here can give you that info.

 

[epaultmbt]

Yes, in front and behind. Shoots and looks great. Easily have enough MB to mount a suppressor. It's amazing how much weight the MWS carries in the barrel.

 

[BRguy]

Jrhtx
No
I just read with great interest the new issue of Sniper and it was suggested (can't recall who) that fluting a barrel was very detrimental to accuracy.

When I get home I can look up who wrote it and the reasons why unless someone here can give you that info.

Um......wait what....

Im running out of fingers counting sub moa guns with fluted barrels

 

[savagenut]

Had adco reduce the diameter of my 16" barrel to .750 front and back of the gas block. Installed a lightweight railed forfend and the weight savings was dramatic. No loss of accuracy either. Highly recommend this to make your .308 more carry friendly.

 

[newguy2k3v2]

I'm having mine dimpled right now.

 

[TXTransplant]

I also had Adco turn an AR barrel down to .625 from a heavy profile and noticed no loss in accuracy. The only thing I noticed was the front end of the gun weighed a pound and a quarter less.

 

[DogBone87]

Had adco reduce the diameter of my 16" barrel to .750 front and back of the gas block. Installed a lightweight railed forfend and the weight savings was dramatic. No loss of accuracy either. Highly recommend this to make your .308 more carry friendly.

I take it that you're not referring to a MWS but maybe another 308?


We need the specifics to make this thread interesting. Before and after weights or something. And pictures are worth 1000 words..... Jus sayin

 

[Bravo 1]

Um......wait what....

Im running out of fingers counting sub moa guns with fluted barrels

JRHTX,

The article is written by Mr. Tom Beckstrand and is on page 8. The part about the barrel fluting is way to long to type and like you I am getting older-60.

The article is about Accuracy International and it's attempts to win the coveted contract from SOCOM's Precision Sniper Rifle. In the article and I quote

" One design change that resulted from AI's exaustive accuracy testing and development for the PSR is the removal of flutes from the barrels. Engineers at AI decided to isolate the barrel flutes to see what impact they had on accuracy. They discovered that no matter which flutted barrel they used, impact would diverge as the barrel heated. The POI shift from a warming barrel greatly diminihed when they used barrels without flutes." Later on still quoting- Engineers determined that the flutes never heated evenly, causing POI shift. I hope the results of this test gain wide circulation through the sniper and long-range shooting communities to help elimate some of the ignorance that surronds the perceived advantages of barrel flutes."

I hope this helps in your decision and wish you the best of luck.

I guess we all could learn something from internet commandos such as BRguy however we would be less informed. By the way, if some of the words are to big for you BRguy, they still have things called Dictionaries...I suggest you find one and use it.

 

[jrhtx]

I take it that you're not referring to a MWS but maybe another 308?


We need the specifics to make this thread interesting. Before and after weights or something. And pictures are worth 1000 words..... Jus sayin

Agree, weights and pictures would be great. I need to put the factory 16" on the scale. I know it is a fence post.

Bravo 1 - Thanks for the quote. I haven't seen that magazine on the stands anywhere. I will try to find it. It is interesting that my AW 300WM is factory fluted.

 

[Bravo 1]

Hey. Send me an IM with contact info if you can't find it. Will make copy and send it to you.

 

[Masked]

I've read the article as well and I understand the point they're trying to make -- That flutes aren't a precise cut which, they aren't so, heat dissipation will differ and thus there will be unevenness but, the reality is that we're not discussing +1 MOA or even a 1/2 MOA difference, we're discussing @1/16 of a difference.

In English, your flutes aren't perfect because of how they're cut so, that imperfection causes "issues" as compared to the barrel just being contoured and left that way...So after your 2nd or 3rd shot, the "theory" is that your flutes, because they're uneven are now different temperatures (I dumbed that down) thus causing more spread.

Now, I'm no expert on fluting and/or contouring but, heat dissipation is something I'm overly familiar with...I'd LOVE to see someone take an accurate reading with equidistantly spaced shots with an HDEIT or similar...I think you'd find the temperature difference is minuscule at best.

I don't think we're discussing enough of a difference to warrant NOT fluting a rifle but, the theory does hold water.

What would also be interesting is to break down the heating differentials (I wish AI had done this) between Chrome moly + SS and then coatings like Cerakote, Duracoat and Ceramic...

 

[Bravo 1]

Mask

What you are saying is correct but having said that is it not fair to suggest if it did help to flute a barrel or by doing so made the weapon more accurate then AI would do so especially given the fact they were in the running for the contract?

 

[Masked]

Mask

What you are saying is correct but having said that is it not fair to suggest if it did help to flute a barrel or by doing so made the weapon more accurate then AI would do so especially given the fact they were in the running for the contract?

We really don't know how MUCH of a difference fluting really makes -- AI didn't go in depth enough (Or maybe they did, we just don't have the info) to really give us any specifics so, what we do actually know is that theoretically fluting does (If done imperfectly) cause issues with accuracy but, again, we don't know how much of a difference, if there's a big difference, we only know that it makes a difference.

IMO, if AI is going to come out and say this...Especially in a magazine "most" of us read, there needs to be substantial evidence...Not just, we tested it and fluting made a difference.

What were the temps? What was the flute depth? Did you test multiple depths? Did you test different coatings? Chrome Moly VS. SS?

There's so much we just don't know that all we can really say is that, in theory, what they're saying makes sense but, nobody has confirmed it really, yet.

You also have to keep in mind that fluting in general may not be the issue...The issue may be solely how/who did the fluting in the first place...

I don't think this really effects you or me to the extent that the article made it sound like it did (That was the vibe I got, anyway)...But, you'd really need to gun it after repeated shots to tell if the dissipation is uneven...

 

[Bravo 1]

All I'm saying is that it must have been enough of a difference or AI would flute their barrels

I'm sure that the protocols and procedures they have in place would be way over most of our heads unless one has a degree in engineering.

If anyone wants to flute their barrels that's fine.

I was as just trying to shed some light on this subject. Nothing more....nothing less.

 

[Masked]

All I'm saying is that it must have been enough of a difference or AI would flute their barrels

I'm sure that the protocols and procedures they have in place would be way over most of our heads unless one has a degree in engineering.

If anyone wants to flute their barrels that's fine.

I was as just trying to shed some light on this subject. Nothing more....nothing less.

No, I'm with you 100%...What I'm saying is that, I wish AI had given us some data to back up that claim.

I can stand here and say my monster truck goes 200mph, put it in a magazine and start throwing 200mph speedometers on monster trucks...It doesn't mean that truck can go 200mph...

What AI is saying makes sense to a degree but, as to how much it makes sense nobody really knows but, AI.

What we DO know is AI doesn't flute their barrels because they have "evidence" it impacts accuracy...Well...Where's that evidence? -- That's all I'm saying.

I can understand WHY it would impact accuracy...But, I want to see the evidence backing up that claim rather then "We tested it and fluting is bad".

 

[Bravo 1]

I hear you brother however the little guy like you and me might not ever find out. Interesting though.

 

[Engine 22]

Well, I guess that my barrels that are fluted didn't get the memo they lost accuracy after fluting......weird.

 

[Bravo 1]

Well, I guess that my barrels that are fluted didn't get the memo they lost accuracy after fluting......weird.

Hey I'm happy that you are happy.

 

[savagenut]

DogBone87-
You're right, had it done to a DPMS LR 308 with 16" heavy barrel. Adco profiled the barrel behind the gas block to .675 and .750 in front. With optics, sling and front vertical grip the rifle is about 11oz. lighter than stock. The lighter front is real noticeable after carrying it all day in the woods. Don't have any pics of the barrel before the 12" forend was mounted.

 

[KevinB-KAC]

A few years ago we (KAC) did a Thermal Study on barrels with some .gov support.

Fluted barrels will yaw through the heat cycle. Now on a bolt gun, my guess is your going to see a significant issue. However doing it in a gas gun is not a great idea.
Stress is imparted in fluting, and no matter how well you flute the barrel will have inconsistent stresses, add in heat and it will start to yaw in a specific direction.
That is part of the reason we 'dimple' out barrels as it was found that if dimpled correctly the stresses imparted are not linear, so it will not yaw.

Now if you knew what temp your fluted barrel was - you most likely could predict where the POI would be moving to, as the results seem to be very repeatable for given heat cycles in the same barrel.

 

[swampbuck]

Fluting barrels may theoretically deminish accuracy to a bench rest shooter but it is academic at best. Fluting when done properly should not affect 99.9% of shooters. Especially not gas guns.

 

[Masked]

A few years ago we (KAC) did a Thermal Study on barrels with some .gov support.

Fluted barrels will yaw through the heat cycle. Now on a bolt gun, my guess is your going to see a significant issue. However doing it in a gas gun is not a great idea.
Stress is imparted in fluting, and no matter how well you flute the barrel will have inconsistent stresses, add in heat and it will start to yaw in a specific direction.
That is part of the reason we 'dimple' out barrels as it was found that if dimpled correctly the stresses imparted are not linear, so it will not yaw.

Now if you knew what temp your fluted barrel was - you most likely could predict where the POI would be moving to, as the results seem to be very repeatable for given heat cycles in the same barrel.

That's what I figured because the dissipation can't disperse evenly so, there are inconsistencies.

Good to know there's some truth behind this.

Any chance that data is FOIA?

 

[StoopidSlow]

Well, I guess that my barrels that are fluted didn't get the memo they lost accuracy after fluting......weird.

Well Bravo 1 read it in a magazine so obviously hes the expert here, we must defer to him.

BTW awesome tangent, really getting at the heart of OP's post

 

[Masked]

Well Bravo 1 read it in a magazine so obviously hes the expert here, we must defer to him.

BTW awesome tangent, really getting at the heart of OP's post

The individual from Knights Armory confirmed this a few posts above yours...Would have helped you to read a bit further.

A few years ago we (KAC) did a Thermal Study on barrels with some .gov support.

Fluted barrels will yaw through the heat cycle. Now on a bolt gun, my guess is your going to see a significant issue. However doing it in a gas gun is not a great idea.
Stress is imparted in fluting, and no matter how well you flute the barrel will have inconsistent stresses, add in heat and it will start to yaw in a specific direction.
That is part of the reason we 'dimple' out barrels as it was found that if dimpled correctly the stresses imparted are not linear, so it will not yaw.

Now if you knew what temp your fluted barrel was - you most likely could predict where the POI would be moving to, as the results seem to be very repeatable for given heat cycles in the same barrel.

 

[Bravo 1]

Well Bravo 1 read it in a magazine so obviously hes the expert here, we must defer to him.

BTW awesome tangent, really getting at the heart of OP's post

I was just trying to inform all what I read. It's up to the individual to consider this if he decides to have the flutes or not. I thought the whole idea of this site was to try to help others. I guess not.

BTW your signature seems to be fitting.

 

[jrhtx]

Thanks for all the responses and discussions.

If I can get home at a reasonable time tonight I want to break down the upper and weigh all the parts and will post the info.

 

[KevinB-KAC]

* I just realized I should have proof read my comment prior.

I had meant on a bolt gun you probably would not see major issues due to the fact the rate of fire is so low compared to the gas guns.

 

[Masked]

* I just realized I should have proof read my comment prior.

I had meant on a bolt gun you probably would not see major issues due to the fact the rate of fire is so low compared to the gas guns.

[MENTION=7341]kevinb[/MENTION] - Are any of the results from the thermal testing, public and available?
[MENTION=7289]jrhtx[/MENTION] - I would go with dimpling -- Looks cool and works...

 

[jrhtx]

Just for reference, a Gen 2 MWS upper weights
6# 11 oz - Complete upper, 16" chrome barrel, flash hider, bolt, charging handle, 3 KAC rail covers. NO scope, sights or other accessories
3# 5 oz - Barrel with gas tube, flash hider
2# 4 oz - chassie with chassie bolts and 3 KAC rail covers. NO charging handle, bolt, sights or other accessories.

Somewhere I have 3"+/- of barrel stub off a GAP 10 I will weigh to see what the 13.5" may weigh.