Help Indexing Flutted Barrel

S

sj-pratt

Guest
Installing My First Flutted Barrel And Was Wondering How A Pro Would Allow For The Extra Travel I Got When I Tighten The Barrel.
Now I Will Have To Set The Barrel Back In The Lathe And Do Over Again. Was Just Hoping Someone Could Offer A Little Advice

Thanks
Steve
 
I guess I'd fit the tennon first to the action (with the tenon length left long), face the tenon shoulder until the barrel indexes properly, THEN face the tenon to the proper length, and finish chamber.
 
Steve, Don't know about the "PRO" bit. I have been fluting barrels for a very long time. I do basicly what msalm says. I use 8 flutes and normally put a valley up. I only do Remington 700 actions so have the advantage of different thickness recoil lugs. My normal proceedure with a new barrel is:

New centers, turn cleanup at breech end, turn for threads, flute, thread, fit to action, chamber. When fitting to the action, I sometimes use different thickness recoil lugs.

Don
 
Installing My First Flutted Barrel And Was Wondering How A Pro Would Allow For The Extra Travel I Got When I Tighten The Barrel.
Now I Will Have To Set The Barrel Back In The Lathe And Do Over Again. Was Just Hoping Someone Could Offer A Little Advice

Thanks
Steve

I'm not a pro with fluted barrels but the key is to tighten it up and see where it indexes and then go from there... there is no way of predicting where it lines up until the first tightening... I usually charge a bit more for indexing fluted barrels and installing brakes that require indexing... it takes more time...
 
Help Indexing Fluted Barrel

When fitting a fluted barrel to a Rem 700, I adjust the torque shoulder on the stub to come up 10 degrees short when tightened by hand in the lathe. That allows the barrel to be turned into the proper position with the wrench and vise with the tightness I want on the barrel.
 
THANKS FOR THE REPLIES I LEFT A LITTLE FOR TIGHTNING BUT NOT QUITE 10 DEGREES AND OF COURCE IT WAS WRONG. I LIKE THE IDEA OF FITTNG TO ACTION THEN FLUTTING BUT I HAVE READ FLUTTING IS BEST DONE BY BARREL MAKER.:confused:
 
I've fluted all my barrels in house for 12 years now. I'm not aware of any problems. Do the barrels change? I'm sure they do. Do those changes show up on the target? I haven't seen it.

Dave
 
Dave

Can you give a brief description of the setup and step you use.

What size/type cutter?
Do you cut a flute than rotate the barrel 180 degrees and cut an opposin flute or just cut each flute in order?
Whats the smallest contour on a hunting rifle you flute. In order to make a light weight rifle.

Hal
 
I've never paid any attention to or cared where the flutes lined up on the barrels I've installed for myself. Am I missing something other than just the looks?
 
Hal
here are a couple of pictures. I get my cutters from AB Tools in CA WWW.abtoolsinc.com I don't let them get dull. I have them resharpened after about 10 barrels. I use a mist coolant system.

I use a standard 5c collet spinner on one end to index the barrels. I made the plate and center for the other end. I built in more range of adjustment than I needed. It can be a lot simpler than what you see. When I made the supports for the rear of the barrel I knew I would be doing a wide range of barrel diameters. The only way to make money in this business is to have quick, simple setups. I made the supports from 3" aluminum and drilled the hole off center so they would swing around and work for every diameter barrel. One support has another eccentric sleeve over it to hold a clamping screw that I use when fluting hunting barrels. They want to rebound away and cause chatter if I don't use it. Heavy target barrels don't require the addional support. I've found all I need is two supports for any length barrel. I have fluted #2 barrels before. Once you get to a #4 and under it mostly for looks. Yes I do go 180 degrees. The sequence for 6 flutes is,0,180,60,240,120,300 degrees

I'm going to be fluting some barrels as soon as a cutter gets back from being sharpened. I'll take a picture of everything all set up and post it. As long as everything is tied down tight this setup works great. It will let you know when something is loose. I have .219", .250", .250 flat botton w/radius corners, and .3125" cutters. I have 5 total so that's over $1000 invested.

Dave
 

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Thanks Dave That Would Be One Way I Could Get The Flutes In The Right Place.
 
When I do mine, I use a different method from what Dave uses but the idea behind it is similar. I think my setup is more rigid though, and involves less parts. This setup will not work for a straight barrel though unless you could make oversize fixtures for on the barrel, one with flats and one round.

Let's say I'm doing a 1.250" tapered barrel.

I start with a round of aluminum. Put it in my index head and mill flats on it equal to the number of flutes I want which in MY case is 12. I like shallower flutes and more of em. I think it looks nicer and that way nobody cares about how they line up when it's done, least of all me. That piece of aluminum is sitting here at 1.5" long after cutting off.

The flats machined on it are such that across any two flats, you have 1.250" (the barrel diameter whatever it is) and the part is still connected to the round from which it was made. Now go to the lathe when you have 12 equal flats.

Face the part, and now bore the part to have a taper that matches exactly the end of your barrel. Cut the part off and de-burr it and now you should have something that socks on the end of the barrel like a morse taper. It also allows you to set up a barrel on a flat surface so as to have the bore centerline in a horzontal plane with the untapered breech end of the barrel laying naked on the table.

Go back to the mill. In the case of a manual hand cranker, set the barrel on the mill table such that the side to be cut is perpendicular to the y axis (forward and away). This means that an indicator on the vertical centerline of the barrel moves little to nothing as you move teh mill table left and right. Now bolt step blocks in behind the barrel so as to make a repeatable stop to push back against and don't forget to also add a stop on the end so that the position of the barrel on the table is the same every time in the X axis (side to side). Position that stop to also help hold the part from sliding when the cutter is cutting and trying to push the part. Example, if the cutter is climb milling, put the stop behind the cutter so the part does not get sucked into the cutter. I always climb mine but I'm using an NC mill. I probably still would if I was using a manual. Cutters last longer when climbing if done properly.

Now, with your 12 flatted piece on the barrel, you can index the barrel precisely and the barrel is no more than it's height away from the table. Don't allow the fixture to come off the barrel or knock it off before you finish all flutes or you're gonna be sorry. Mine need a hammer to remove so you needn't worry about it falling off. Use step blocks and clamps to bolt the barrel down securely and flute away. I also when doing this place one more hunk of steel behind the barrel so it cannot flex away and secure that baby to the mill table as well. It's just laying against the back of barrel and bolted down to the mill table. I have no photos to show this but I'm sure it's easily enough understood.

So you have, 2 locating flat stops at each end of the barrel on the sides of the barrel. 1 stop to locate the barrel on its end, and a backup plate behind the barrel in the center of the unsupported area to help keep it from flexing away. Then you've got two clamps holding it down for dear life and you're ready to go. If you want some taper in your flutes like I do, build that into your setup. I usually do .090 at the breech end and .050 or .060 at the muzzle. It's not visibly noticeable and if it was who would care.
 
Hi Phil

I'm sure your way works but by the time your ready to start fluting I'm about done. I can put in another barrel line up the edge with an indicator and take off again. How rigid does rigid have to be? I get better finishes than any barrel I've ever ordered fluted.



Dave
 
Dave,

I was just offering another way to skin a cat, not really making a comparison per-se. If you included your time to make fixtures along with the fluting job as I did here, and the cost fo the 3" diameter aluminum, you might find you'd be spending a few extra hours too. And let's face it, nobody in their right mind, regardless of how much equipment they have, would do this for themselves.

Short of having a fourth axis mill at your disposal, paying for this to be done by someone such as yourself is the best spent $100 a guy could have.

Just fyi, I made my own toolholder (arbor) and use the blade style cutters instead of the one piece versions as you're using here. They're quite a lot cheaper. That is some serious bucks in cutters there. :eek:

I also get a nicer finish than the ones I've seen done by barrel makers but that's not saying a whole lot. I do not doubt for one second that you do better work than what I've seen. Especially when someone goes to de-burr the barrel and slips off with the burr knife and gouges the barrel on every single flute, multiple times each. :D
 
Sj

Installing My First Flutted Barrel And Was Wondering How A Pro Would Allow For The Extra Travel I Got When I Tighten The Barrel.
Now I Will Have To Set The Barrel Back In The Lathe And Do Over Again. Was Just Hoping Someone Could Offer A Little Advice

Thanks
Steve
,,,,,,,,,,,,,

If the thread is tight and properly fitted and it slams the opposite shoulders with a BANG. You can test the receiver on/off try to index the flutes while you working on the barrel.All my threads fit that after a bang contact of shoulders is made there is about 1mm of extra movement afterwards, regardless of how much torque is applied.

Shoot well
Peter
 
Phil
I know. It was a poke at engineers as much as you. All in fun. Yes I had some time making the fixtures to start with but they and my mill have more than paid for themselves fluting barrels. It's the only operation I can do in conjunction with any other work in the shop. I've fluted about 200 barrels or more so the cost of the fixtures is down to nothing now. As far as the cost of the cutters, either your in this business or your not. It takes tooling and equipment to get the job done.
I've got a deburring tool for keyways but I still manage to gouge a barrel from time to time. Always on the end of the flute so it's not to hard to polish off.
Going to try and make the World Open this year. See you there.

Dave
 
Dave,

I can see where you're coming from on the tools you have tho. If they cost that much, somethings tell'n me they're nice cutters. We've got literally 5 gallon buckets of the wheel types around the shop in various sizes so I just use what's on hand. The only trouble is, I don't have a good supply of the ones for this sort of work unless I take a bigger one and grind it myself and life it just too short for that. I have found myself though spending more and more for all the tooling I use for all my "Government" projects around the shop. When a guy want's to do more than one job with that tool, don't waste yer time gett'n the cheapo version cause all you do is buy 10 of em later. That 1K in 5 tools don't surprise me one bit.

I don't do anywhere near that many barrels. I do my own just cause Shilen won't. There's a big difference between doing one or two here and there in my spare time and being able to get enough done so customers are happy. You'd be starved to death doin em my way, that's fer sure. No Lie, I bet a 12 flute barrel in my 2 axis CNC takes 4 hours. Now, I'm usually working during that time (doing real honest for money work!) so it's not like I'm just standing there waiting for the mill to finish but holy cow, I think I'd sooner go to the dentist. Understand I have to run back and forth from one end of the shop to the other watching two machines at the same time. It's a real hoot.

I do like your eccentric idea for all barrel sizes. That's pretty cool. Especially when you're doing different stuff in lighter contours. Mine are all exactly the same barrels for light guns so my one fixture is all I'll ever need. And seriously, if Shilen would flute them for me, I'd never do it. It's one thing to have a setup and be ready for the job. It's another to re-invent the wheel every time. That'd be ok if I thought making chips was cool but, my days of playing on the mill for fun have been gone since about 1 lifetime ago. I just want it done, whatever the job.

Hey, it's the 40th anniversary World Open this year so make certain you can get up here. I'll buy ya a beer r 3. We're callin the local water'n hole a few weeks before and tell'n em that they better stock up for that weekend with good beer. We've got good people in charge of every aspect of the match and it's gonna be worth the trip. I can't offer you any of that turpentine you guys drink but if ya bring some of it along I'd join ya fer a small spash. There's gonna be a great bunch of prizes again and it'll be spread out probably even better'n it was last year. You know how it goes, always trying to make it better. They make roads that head north ya know, make it a point.
 
Dave Tooley - Yes I do go 180 degrees. The sequence for 6 flutes is,0,180,60,240,120,300 degrees

I guess this is to induce stress equally, but could you explain what this does different than just rotating 60 degrees each time?

Thanks Gary
 
Gary,

In CM steel, he's probably going to tell you that is mandatory. But on a SS barrel, it might be optional. However, if a process is known to help one item and known not to hurt another, being consistant is wise.
 
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