Gunsmithing Spiral fluting of barrels

[RTH1800]

Does anyone know who will sprial flute rifle barrels?
Thank You
RTH

 

[deadly0311]

Re: Spiral fluting of barrels

Kampfield Customs

 

[RTH1800]

Re: Spiral fluting of barrels

Thank You
RTH

 

[MinorDamage]

Re: Spiral fluting of barrels

Kampfeld cannot do them right now due to "patent infringement" claims by ER Shaw. Look it up, but they have suspended all spiral fluting work on barrels.

Josh

 

[Emouse]

Re: Spiral fluting of barrels

patent infringement my backside!

how do you "patent" a common engineering process????

thats almost as ludicrous as the claim of "cross drilling" found in one well known recent US silencer patent..

 

[txlimey]

Re: Spiral fluting of barrels

"patent infringement my backside!

how do you "patent" a common engineering process????"

I have to agree with Emouse on this one. Spiral or Helical fluting is a common engineering process.

EW Shaws patent was only granted in 1999. I have an enginerring book that references the principal, and that was published in the 1940's.
Just because EW Shaw were given a patent means nothing. They might be in violation of an earlier patent granted to someone else.
I know of a case locally where someone had been granted a patent for the use of an electrical PID loop in HVAC system. They were suing over patent infringment. The defendant used a piece of published material from my company to prove that that process was in the public domain 20 years prior to the granting of the patent.

 

[19Scout77]

Re: Spiral fluting of barrels

Here is a link to the full text of the E.R. Shaw Patent.

http://www.patentstorm.us/patents/6324780/fulltext.html

I'm no engineer, but it sounds to me like Shaw's protected barrel is made to rather exacting specifications, and by altering the relationship between the flutes and the rifling, you could argue no infringement (as well as about a BILLION other potential arguments against the enforceability of the patent). Another way around it would be to have the flutes spiral the opposite direction of the rifling.

The threat of a lawsuit is often as effective as a valid patent.

 

[Kells81]

Re: Spiral fluting of barrels

Its all about cost. It would cost Karl more in lawyer fee's to take it to court than he makes off doing the fluting. Lawyers cost money, Court cost time.

 

[19Scout77]

Re: Spiral fluting of barrels

That assumes Shaw has the resources to do more than threaten.

 

[Adam B]

Re: Spiral fluting of barrels

they will patent haircuts next

 

[BHP9]

Re: Spiral fluting of barrels

PGWDTI do spiral fluting.

www.pgwdti.com

I have 2 rifles with it.

 

[Kells81]

Re: Spiral fluting of barrels

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 19Scout77</div><div class="ubbcode-body">That assumes Shaw has the resources to do more than threaten. </div></div>

Shaw probably pulls in at least a mil a year off barrels and services. Do you think they only make barrels for one time customers? They know the spiral fluted barrels look cool and is one of the only reasons I could think of for someone to order one of their barrels. If someone like Karl would do it to an existing barrel which they will not then they are losing a barrel sale.

It doesn't take much money to Sue someone hell lawyers will work Pro-Bono(spelling) on something like that. It takes money to hire a lawyer to defend against these guys. Karl is essentially a one man operation maybe makes 70k a year and works everyday to make that. Hell look at Larue, it seems they get a new lawsuit from ARMS on a daily basis. All over the use of a number or word.

As far as PGW, they are a Canadian company I am not sure a US patent would effect them.

 

[frog5215]

Re: Spiral fluting of barrels

Not pro bono. That's free.
What you mean is working on a contingency basis: payment comes out of any settlement.
The lawyer may take up to 1/3 or more of awards.

 

[19Scout77]

Re: Spiral fluting of barrels

You'd have about as much luck finding competent counsel to handle a patent infringement case on a Pro-Bono basis as you will contingency! Ain't gonna happen.

 

[Kells81]

Re: Spiral fluting of barrels

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 19Scout77</div><div class="ubbcode-body">You'd have about as much luck finding competent counsel to handle a patent infringement case on a Pro-Bono basis as you will contingency! Ain't gonna happen. </div></div>

Dude it doesn't have to be competent Hell it would just have to have a heartbeat and possibly a pulse. My point is it doesn't cost much to sue someone, but it cost quite a bit to defend against being sued. Especially if your a one man show.

 

[MinorDamage]

Re: Spiral fluting of barrels

Wasn't attempting to start something here. I just wanted the OP to know that Kampfeld had suspended services due to the claim. I think it is crazy as well, but that patent is about as obtuse as possible and it would be one lengthy battle if you tried to prove in Kampfeld's favor. I love the look of the Kampfeld fluting and think it is great they do it aftermarket. However, Shaw knew they would be desirable and wanted everyone to have to buy a Shaw barrel. This is a turd the size of the Larue ARMS fight. Some people are just too damn greedy. If it is a legitimate patent claim, sure. If it is something like this, which I almost assume leans more toward "intellectual property" get over it. Go look through some of the patents that the patent office gives away. Not like any other country cares one bit about our patents...

So, yes, I am all for Kampfeld being able to produce spiral fluted barrels. I just wanted the OP to know what was going on.

Josh

 

[Kells81]

Re: Spiral fluting of barrels

I think its dumb too, Karl does a fantastic Job. The Idea of patenting something like barrel flutes is as dumb as ARMS patenting the number 7 or whatever. He turns out a nice product and its a shame that its on hold right now.

 

[bdh308]

Re: Spiral fluting of barrels

And Im calling a BHP9 an asshole for posting two of the prettiest rifles Ive ever seen and making me salivate over them. Nice work! Got to love a PGW.

 

[3wide]

Re: Spiral fluting of barrels

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Poke</div><div class="ubbcode-body">I think its dumb too, Karl does a fantastic Job. The Idea of patenting something like barrel flutes is as dumb as ARMS patenting the number 7 or whatever. He turns out a nice product and its a shame that its on hold right now. </div></div>

I agree, patenting a machining process seems crazy that it actually can be done. E.R Shaw doesn't have to worry about selling a barrel to me. What's next patenting a porting process on a barrel?

 

[19Scout77]

Re: Spiral fluting of barrels

Read the patent. It is far more specific than just protecting a machining process---hence the reason a simple spiral fluting of an existing barrel would NOT infringe the patent.

 

[Hawk4357]

Re: Spiral fluting of barrels

I just got emails back from ER Shaw and PGWDTI saying they will only flute their barrels.Looks like I will check into having my local machine shop do it.

 

[Emouse]

Re: Spiral fluting of barrels

so applying flutes to a piece of steel is a novel and patentable process???

guess we can't make reamers anymore then???

sadly many U.S patents are not worth the paper they are written on!

 

[BugSniper]

Re: Spiral fluting of barrels

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 3wide</div><div class="ubbcode-body">
I agree, patenting a machining process seems crazy that it actually can be done. E.R Shaw doesn't have to worry about selling a barrel to me. What's next patenting a porting process on a barrel? </div></div>

Has anyone not bothered to point out this is properly called a screwjob, literally. I mean, if Shaw wants to be the man claiming to have invented the screwjob.... well actually, maybe his reinventing it.

 

[DoubleGobble00]

Re: Spiral fluting of barrels

Those spiral fluted barrels look nice. I was wondering if anybody did that also.

DoubleG

 

[BOLTRIPPER]

Re: Spiral fluting of barrels

this very topic surfaced at lunch with a couple of gun makers just yesterday......it seems that one do NOT want to spiral cut button barrels for many technical reasons....or for that matter cut flutes on a button barrel.

 

[Averagejoe]

Re: Spiral fluting of barrels

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BHP9</div><div class="ubbcode-body">PGWDTI do spiral fluting.

www.pgwdti.com

I have 2 rifles with it.

</div></div>

Yep! And they are Canadian so go luck to Shaw getting a claim on them boys...

 

[Gunboy2006]

Re: Spiral fluting of barrels

for $750 CAD, they will supplies the barrel flue already, that is an Awesome price.

 

[RollingThunder51]

Re: Spiral fluting of barrels

..

As far as Karl Kamfeld, after speaking with him at length on this subject his recommendation is as follows:

"Please tell anybody that has an interest in any of the products or services that I provide to please call me directly at the shop." 517-456-6388.

There is more to this story than meets the eye.

As to the effects of working on a finished barrel. I have a number of barrels that have had significant work done to their profile both before and after all the bore/chamber work was completed, like everything else, it all depends on who is doing the work and how they do the work. There is no issue with Karl's work.

http://asrealasitgets.net/forums/ubbthreads.php?ubb=showflat&Number=26702&fpart=1

http://www.kampfeldcustom.com/index_002.htm

Karl's work..

Penrod = Schuetzen Octagon, to flutted, to round with the scope rail part of the blank (as in starting out with a 4" Lilja blank) that drives nails (25-06 Ackley). All work done post...obviously.

 

[USMCj]

Re: Spiral fluting of barrels

Guys, am I the only one who thinks that spiral fluting a barrel will only help it warp (bend) faster if you heat it up shooting rapid strings?

 

[oldgrayone]

Re: Spiral fluting of barrels

Food for thought. Why would external flutting make a barrel expand at one rate compared to internal flutting (rifling)???

 

[RollingThunder51]

Re: Spiral fluting of barrels

..

Like extreme rapid firing, with no regard whatsoever for the resulting effects of significant fluting, flaring, finning and banding?

Just kidding.... Here is a very comprehensive review of fluting. Findings as to stiffness, drop (droop) and barrel frequency changes, resulting accuracy found at the bottom.


http://www.varmintal.com/aflut.htm

<span style="font-weight: bold">"ADDING IT ALL TOGETHER.... After including where the muzzle is pointing at the 100 yard target, the bullet drop on it way to the target for each shot's muzzle velocity, and finally the downward velocity of the muzzle swing as the bullet exits, the results show only a slight difference between the 5.420 lb Light Fluted Barrel with the 0.8" muzzle diameter and the 6.653 lb Heavy Fluted Barrel with the 1.222" muzzle diameter. The baseline 6.657 lb non fluted barrel has a maximum spread of 0.7262 with the same five shots. Fluting the baseline barrel showed a reduction in group size of about 21%. Keeping the same weight and fluting the barrel with a 1.222" muzzle diameter reduced the group size by 23%. If fluting is done without introducing large residual stresses in the barrel it should improve accuracy by as much as 20% over a solid barrel of the same contour."</span>

<span style="font-weight: bold">Spiral fluting not covered...

This from Fulton:</span>

====================================

A engineer's perspective on fluting:

These discussions on fluting are guaranteed to produce lots of controversy!

All you really need to know is that as you take material off you reduce the stiffness.

So long as the material properties remain unchanged (specifically, the material strength), you CANNOT remove material from ANY shape, and make it stronger! A clever engineer, however, can move material to make the part stronger...

Anyhow, in a humble attempt to end this controversy for once and for all, I've decided to try a cold, hard, mathematical analysis of a typical real-world situation.

Given:

* Weight is directly proportional to cross-sectional area. (Specifically, the weight is equal to the cross-sectional are times the length, times the material density.)

* Rigidity (stiffness) is directly proportional to Area Moment of Inertia.

* Surface area is directly proportional to the outside perimeter. (Specifically, the surface area is equal to the perimeter times the length.)

Both "givens" are per every basic engineering Statics text.

Test subject barrels:

1. Remington 700VS:

* outside diameter: 0.850"
* bore: .300 bore with six .308 grooves, 50% grooved
* flutes: none
* Cross-sectional area: 0.493 sq.in.
* Area Moment of Inertia: 0.02489
* Perimeter: 2.666"

2. Remington 700VSF:

* outside diameter: 0.850"
* bore: .300 bore with six .308 grooves, 50% grooved
* flutes: six, 3/16" wide, 3/16" deep, full radius
* Cross-sectional area: 0.312 sq.in.
* Area Moment of Inertia: 0.01411
* Perimeter: 4.276"

3. Hypothetical barrel for comparison:

* outside diameter: 0.7005"
* bore: .300 bore with six .308 grooves, 50% grooved
* flutes: none
* Cross-sectional area: 0.312 sq.in.
* Area Moment of Inertia: 0.01127
* Perimeter: 2.197"

Comparisons:

0.850" Fluted vs. 0.850" Plain:

* Cross-sectional area (weight): 36.7% less
* Area Moment of Inertia (rigidity): 43.3% less
* Perimeter (surface area): 60.4% more

<span style="font-weight: bold">Conclusion: the fluted barrel is much lighter, much less rigid, and has much more surface area than a solid barrel of the same diameter.</span>

0.850" Fluted vs. 0.7005" Plain:

* Cross-sectional area (weight): *same*
* Area Moment of Inertia (rigidity): 25.2% more
* Perimeter (surface area): 94.6% more

<span style="font-weight: bold">Conclusion: the fluted barrel is significantly more rigid, and has much more surface area than a solid barrel of the same weight.</span>

Notes:

* All section properties are courtesy of the 2D Properties module of Ashlar Vellum 3D version 2.70 (my favorite CAD program), based on my layout of the sections.

* Measurements of the 700VS were taken from an actual 700VS from my personal collection.

* I didn't actually have a 700VS on hand, but have recently compared one to a 700VS side by side (while deciding which to buy), and verified that the barrel outside diameters are the same. Flute dimensions are approximate, but should be fairly accurate. After ten years as an engineer, I have a good eye for dimensions; I know for sure that the flute width was much more than 1/8", and definitely less than 1/4"; 3/16" should be quite close. Likewise, I noted for certain that the flutes were full radius, and deep enough that the radius started approximately 3/32" below the outside diameter. Despite any minor errors, the fluted barrel described is certainly representative of the Real World, and the trends are quite clear from the analysis; the effects of fluting are significant. A 1/16" here or there would not noticeably change the results.

* The weight and surface area comparisons hold true only for the fluted portion of the barrel. On every fluted barrel I've seen, the fluting does not begin until well forward of the chamber (6"-9"), and ends from 1"-4" from the muzzle. For example, on the Remington barrels presented, only approximately 65% of the barrel is actually fluted, so you will only realize ~65% of the weight savings and surface area increase. Also, I've seen some fluted barrels where the fluting is more shallow and/or narrow than the examples presented. Hence, the effects of the fluting would be less than reported above.

* I also did a quick analysis of a fluted barrel with shallower flutes; I won't present the entire analysis here, but in summary, a barrel of the same weight also had a larger diameter, and the differences in stiffness and surface area were simply less pronounced than the barrel detailed above. Extrapolating: as the flutes become smaller, the effects diminish; as the flute dimensions approach zero, the fluted barrel (and the barrel of the same weight as the fluted barrel) simply becomes the original bull barrel, and there's no effect. Conversely, as the flutes get larger, the effects become more pronounced; eventually, though, one would run up against a geometrical limit (the flutes colliding, or reaching the bore). Under NO geometrically possible conditions can flutes make a barrel MORE rigid than a plain, unfluted barrel of the same diameter.

* Before someone asks: no, the number of flutes has no real effect on these conclusions. Four (or fewer) flutes of the same size would simply remove less material and hence reduce the effects shown. Eight (or more) flutes might increase the effects, but would tend to collide more easily (less room for material between the flutes), so in reality they would tend to have less depth, and hence limit the effects achievable.

..

 

[Marriedman1]

Re: Spiral fluting of barrels

Karl said call his shop..talk to him on your problem to have a barrel spiral fluted. He has a way to do it.

 

[smartrrrs]

Re: Spiral fluting of barrels

DAN HARDING ENGINEERING NEW ZEALAND DO SPIRAL FLUTE SERVICE AS WELL AS OTHER SERVICES SUCH AS ULTRA MATCH BARRELS ,OVER BARREL SILENCERS AND BLUE PRINTING THE ACTION OF YOUR GUN WHAT EVER THAT IS. HOPE THAT HELPS.

 

[excess]

Re: Spiral fluting of barrels

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: oldgrayone</div><div class="ubbcode-body">Food for thought. Why would external flutting make a barrel expand at one rate compared to internal flutting (rifling)???</div></div>

The outside diameter of the barrel has a whole lot more effect on this than the inside dimaeter.

That writeup that varmintal did was on straight flutes if I recall. I will have to think about this and maybe build a model like Al did - my gut instinct is that the spiral fluting indeed causes the barrel to behave differently than straight fluting.

 

[300sniper]

Re: Spiral fluting of barrels

i'm no engineer but i have to believe that a spiral fluted barrel would be less rigid than a straight fluted barrel the same od and with the same size and number of flutes. the first thing that comes to mind is spiral flutes remove more material from the od of the barrel. next thing that pops into my mind, although not quite as dramatic as a spiral fluted barrel, compare the stiffness of a spring to a tube made from the same material with the same internal and external dimensions.

 

[Youngjoonni]

Re: Spiral fluting of barrels

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: nzsniper</div><div class="ubbcode-body">DAN HARDING ENGINEERING NEW ZEALAND DO SPIRAL FLUTE SERVICE AS WELL AS OTHER SERVICES SUCH AS ULTRA MATCH BARRELS ,OVER BARREL SILENCERS AND BLUE PRINTING THE ACTION OF YOUR GUN WHAT EVER THAT IS. HOPE THAT HELPS. </div></div>

How about you turn your CAPS OFF!!! It's ANNOYING and against the posting rules.

Have a nice day.

 

[ainnamor]

Re: Spiral fluting of barrels

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Youngjoonni</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: nzsniper</div><div class="ubbcode-body">DAN HARDING ENGINEERING NEW ZEALAND DO SPIRAL FLUTE SERVICE AS WELL AS OTHER SERVICES SUCH AS ULTRA MATCH BARRELS ,OVER BARREL SILENCERS AND BLUE PRINTING THE ACTION OF YOUR GUN WHAT EVER THAT IS. HOPE THAT HELPS. </div></div>

How about you turn your CAPS OFF!!! It's ANNOYING and against the posting rules.

Have a nice day. </div></div>

Relax man. Way to make the new guy feel welcome.

 

[Nachtadler]

Re: Spiral fluting of barrels

Robert Snyder of RWS Gunsmithing will spiral flute barrels. Check out rwsnydergunsmithing.com.

 

[19Scout77]

Re: Spiral fluting of barrels

All the guessing about the potential negative effects of spiral is just that--guessing.

I have a spiral fluted border barreled .308 that shoots fantastic, hot, cold or lukewarm

 

[Cigarcop]

Re: Spiral fluting of barrels

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 19Scout77</div><div class="ubbcode-body">All the guessing about the potential negative effects of spiral is just that--guessing.

I have a spiral fluted border barreled .308 that shoots fantastic, hot, cold or lukewarm </div></div>

I'll second that, have shot mine in all conditions and nothing has changed....neither did their accuracy after I had it done to them, same loads same results.

 

[border_reiver]

Re: Spiral fluting of barrels

Shaw's outside spiral flutes are probably better than their inside spiral flutes...Maybe that's why they're so protective..

 

[M855]

Re: Spiral fluting of barrels

pacnor flutes also

 

[Rarebreed93]

Re: Spiral fluting of barrels

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Nachtadler</div><div class="ubbcode-body">Robert Snyder of RWS Gunsmithing will spiral flute barrels. Check out rwsnydergunsmithing.com. </div></div>

Another shop that does spiral
http://www.twistedbarrel.com/

 

[Rarebreed93]

Re: Spiral fluting of barrels

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rth1800</div><div class="ubbcode-body">Does anyone know who will sprial flute rifle barrels?
Thank You
RTH </div></div>

http://www.twistedbarrel.com/

 

[RTH1800]

Re: Spiral fluting of barrels

Looks like I started something and did not even know it.
RTH