Gunsmithing can a barrel be re-contoured?

[sid]

i have a spare MTU profile barrel (6XC (hawk hill)) already fitted for my action (deviant), it is too long(26") and too heavy for anything but competitions, since i dont do those i was wondering if the barrel could be recontoured.

i was thinking sendero profile, fluted,threaded and only 16" long

is that possible? or will the barrel be f#@$ up afterwards?

thank you

 

[...]

no reason you cant re-contour a barrel....should be fine

 

[fdkay]

Fluting a barrel after it is drilled and rifled is not typically recommended by those seeking precision.
It would likely cost you just as much to have the barrel recontoured and fluted as it would to buy a new barrel.
If you are going to cut 10" off the barrel, that, in itself will result in a lot of weight loss, recontour, even more.
I, personally, would not flute it.

 

[...]

Fluting a barrel after it is drilled and rifled is not typically recommended by those seeking precision.

You do realize most all barrels are contoured after rifling.... right?

 

[fdkay]

You do realize most all barrels are contoured after rifling.... right?

As far as I know, and I could be wrong, the blanks are drilled and rifled as a straight, untapered round stock, then final contoured (which is why you can buy uncontoured barrels)

 

[Xander3Zero]

Does anyone ever really contour OR flute a barrel before it has been rifled?! I think you want to have the barrel drilled and rifled, and then indicated on a lathe true to the bore so that the contour and fluting are concentric to the bore.

 

[Supersubes]

The exact order of operations varies mostly by method between cut and button. The button guys tend to rifle straight cylinders because they must(stress). Whether to contour it or lap it next is shop dependent. The cut guys, since the process is stress free, can contour first if they choose. Really though, it comes down to the shop.

Krieger will recontour one of theirs for $50 plus shipping. I don’t think they’ll do it after the barrel has been chambered. Hawk hill is a cut rifled barrel, but don’t know if they’ll Re-contour it. I’d guess not though. Done properly, it will not hurt it.

Only way to know is to call hawk hill.

Let this be a lesson to you...MTU is for truck axles only! LOL

 

[fdkay]

From Shilen's website:
"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."

Of course, this doesn't necessarily apply to cut rifled barrels.

 

[RTH1800]

Not going to comment on the re contouring or fluting of barrels regarding accuracy but I damn sure would not worry about voiding the warranty on a Shilen barrel. I had one that had a huge void in the metal when turned down and they refused to do anything about it. Told me it "was probably safe to shoot." I would worry more about Stormy Daniels virginity than Shilen's warranty.

 

[natdscott]

You do realize most all barrels are contoured after rifling.... right?

As far as I know, and I could be wrong, the blanks are drilled and rifled as a straight, untapered round stock, then final contoured (which is why you can buy uncontoured barrels)

Does anyone ever really contour OR flute a barrel before it has been rifled?! I think you want to have the barrel drilled and rifled, and then indicated on a lathe true to the bore so that the contour and fluting are concentric to the bore.

Ya'll are indeed incorrect, but for different reasons.

McCameron: if you're going by "most", then "most" barrels are hammered these days. Probably by an order of magnitude. Hammered barrels are contoured, and often even CHAMBERED, while in the hammer. Concurrent, not post.

fdkay, you are right some of the time. But the premium makers like to not be turning down their barrels after they spent so much time and energy and money making such a perfect bore. More on that in a sec.

Xander3Zero: Yeah. Lots. You think wrong, but I know what you mean. Keep in mind though that there is FIRST a clean lathe pass made on a piece of rusted-ass rough stock that was just sawed loose from the pile of steel sitting outside in the parking lot. THEN, they'll proceed one of several ways to creating a pilot-bore near the final diameter...but that still has to be reamed or honed and/or hand lapped up to final dimension. At that point, they can first judge a blank's straightness and toss it if the hole wandered too much, and they ALL wander. If it meets spec, THEN they can rough contour and proceed through the rest of the cost.



I'll repeat m'self some here, but..


Krieger, Bartlein--and I am sure others--rough contour their blanks AFTER rough contouring, and BEFORE final honing/reaming of the bore diameter. Some then proceed to a hand lap. And only THEN is the rifling cut.

Ya gotta get a STRAIGHT and consistent diameter hole before you even fuck with rifling. Rifling is EXPENSIVE. As such, any process (like fluting or outside contouring) that might fuck up the bore dimension AFTER $$$ has been spent on rifling is therefore done before that.

At any point along the process, they can toss a blank in the scrap pile without having spent any more money on it.


But for particularly hammered, and also for some buttoned barrels, it's best not to be effin' with it after it's done. Small alterations like turing a 0.800" muzzle down for a 0.750" sight tennon might not be too bad, but taking the same blank down to a 1/2" suppressor thread can really fuck up the bore dimension right at the point where it matters (maybe) the most.


-Nate

 

[sid]

thank you all for the replies...

sounds almost like i should try to sell the barrel, i have an MTU contoured barrel right now on the rifle, and i cant wait till its shot out ( has 700rounds only through it) but ill be damned if i try to shoot out the second barrel also. .. maybe i just should try only cutting it down to 16", that should save some weight also.

 

[macvrlamm]

why not it is not a big deal most of the barrel makers have cnc and plug in the numbers and go the finish work is not that hard, sand or what ever blast the barrel. flute why. hell the cheep barrel shortener a pipe cutter then crown it but single point lathe cut and contour not as easy but is done all the time

 

[DAVETOOLEY]

I've fluted hundreds of premium barrels the last 30 years both cut and buttoned. Contours from straight 1.350" down to #2 and I've never had a problem that I knew about. In a perfect world the button barrel would be fluted prior to lapping but in most cases that may be splitting hairs.
As far as recontouring a barrel. There are places you don't go like taking a button rifled MTU down to a #3. The bore will change some and may need to be lapped again and that can complicate things if it's chambered and crowned. Take the advice of the manufacturer they know how their steel responds. Not all steel is equal . Recontouring a cut rifled barrel is no different than taking a few more passes when it was made.

 

[natdscott]

Take the advice of the manufacturer they know how their steel responds.

...and if it is a box barrel like Remington, don't ask. Just assume it was hammer forged, and leave it well enough alone.

-Nate

 

[DAVETOOLEY]

A lot of Remington's are button rifled these days.783's from day one and big new automated line in Huntsville for 700's. But I'm pretty sure there is no stress relieving going on after rifling.

 

[sid]

i send in 1 of the barrels to be cut down to 16.5 inch, ill see how i like that, and either do that with the second barrel also when its time or look more into other solutions

 

[Dwilliams88]

You could recontour but it's probably not cost effective.

 

[sid]

I got my barrel back from LRI , went super fast and the work looks very good, I had it cut down to 16.5 and re threaded, they received the barrel this Monday and today Friday I had it back.

Now the rifle is more useful for me, nice looking and compact and not so heavy anymore.

 

[81sfo]

Your rifle turned out good, short and stiff barrels are hard to beat !