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gunsmith_tony
July 01, 2007, 17:15
I know most of you probably don't have access to a lathe. Even so, would you be interested in a photo illustrated (barrel) blank turning tutorial?

colchester
July 01, 2007, 18:53
I would like to see how you turn a blank. I have done it in the past and it proved to be a time consuming operation,however the end results were very good.I would also be interested in the form you use on your cutting tool. Are you using hs or carbide?Chatter has always been the biggest issue for me,I usually have to use the lead mallet trick to dampen the vibration and minimize the chatter.

gunsmith_tony
July 01, 2007, 19:19
I use indexable carbide inserts for most of the turning operations. I grind HSS tools for some of the other cuts like the radius at the chamber opening, crown, grooves, recesses, swivel band grooves and the like.
A follower rest will arrest that irritating chatter. It is a must for turning blanks.

Scalawag
July 01, 2007, 20:22
I'd certainly like to see your tutorial on barrel turning. Post up some pics already!!!:bow:

gunsmith_tony
July 01, 2007, 20:31
Okay. As its very much a work-in-progress, I'll post and illustrate as stages are completed with questions and discussion in between.

gunsmith_tony
July 01, 2007, 20:42
I guess the first point of consideration is selection. Blanks are available from several makers like Douglas, Krieger, Badger, Shillen, E. R. Shaw, etc. Some blanks are better than others as far as quality. But it really depends on what you expect from it and of course the price tag. Material choices are either chrome-moly or 416 stainless. Both have roughly the same machining characteristics and (in my opinion) accuracy potential. I chose a chrome-moly blank for two basic reasons. First, it will Parkerize. Second, I just prefer chrome-moly over stainless. I guess I'm old school.
Most makers will also give you other options for your blank like threading and/or short chambering. I usually get my blanks short chambered. Mostly because all my reamers are finishers. I don't like cutting new chambers with finish reamers, and I don't turn enough blanks to justify purchasing a roughing reamer. And yes...I'm cheap too.
Also, before ordering your blank, measure your barrel at its largest point (usually the outside diameter at the barrel shoulder). Make sure you blanks diameter is adequate. My blank has an OD of 1.250" throughout its 26" length. Yeah...make sure it's long enough too.

Before you make your first cut, you need to check a few things.
(1) Lock the barrel in a four-jaw chuck and dial-in the OD around the chamber area.

http://www.mandmgunsmithing.com/Images/Barrel_tutorial/Barrel_001.jpg

Then indicate on the chamber wall.

http://www.mandmgunsmithing.com/Images/Barrel_tutorial/Barrel_002.jpg

Basically, you want to see if the barrel OD and chamber wall are concentric. This can also be done by spinning the blank between centers. If they are within a couple thousandths then you can proceed to the next step. If not, then it will need to be corrected by making a light cut off the OD about two inches back. Just remember both ends need to be faced off. Usually, a short chambered blank will be faced off on the chamber end by the maker, but not always. And in either case, the muzzle is usually saw cut.

gunsmith_tony
July 01, 2007, 21:15
Now your ready for the big "face off". Chuck about an inch of the muzzle in your four jaw. Indicate close to the jaws and set up the steady rest on the breech end.

http://www.mandmgunsmithing.com/Images/Barrel_tutorial/Barrel_003.jpg

Before facing the breech you need to figure out where to cut the breech face in relation to the chamber depth.
Using your old barrel as a template, insert a GO gage in its chamber. Mike the distance from the face of the gage to the breech face. Use a proper depth mic...not calipers. Now insert the GO gage into the blanks chamber. Face it back to the same dimension + about .010". You want to have a little material to remove with your finish reamer when you headspace it.
Again, using your old barrel as a template, mic the distance from the breech face to the barrel shoulder. You can also measure the distance from your receivers face to its secondary shoulder. Just remember you'll need a little air gap between the breech face and the secondary shoulder. So be sure to subtract about .005" from that measurement.
Now your ready to make the barrel shoulder cut. I usually cut .003" short of the shoulder position and face it. Cut it down to whatever you mike over your threads.

http://www.mandmgunsmithing.com/Images/Barrel_tutorial/Barrel_004.jpg
http://www.mandmgunsmithing.com/Images/Barrel_tutorial/Barrel_005.jpg

gunhead
July 01, 2007, 21:39
Ya know Tony, I am not about to turn any blanks in the near future but Damn, thats a nice Lathe:love:
Rich

gunsmith_tony
July 01, 2007, 21:45
Thanks. A 20" x 80" from MSC. Over kill for most barrel work. :biggrin:

gunhead
July 01, 2007, 22:29
Originally posted by gunsmith_tony
Thanks. A 20" x 80" from MSC. Over kill for most barrel work. :biggrin:

I've been around some of the smallest, largest, oldest & strongest lathes ever made.
Most were from WWII.
Leblonds, Cincinnati's, Lodge & Shipley's, Henley's, American's, Hardinge, etc.
But I am always fascinated with them.
All I have now is a lil bitty one from Harbor Freight:-(
Good for wasting time:tongue:
Cuts, but only small stuff:cry:
Its nice to have a decent size lathe & nice Faux or real Bridgeport.
Nice thread Tony & GL.......
Rich

mountainman
July 02, 2007, 07:13
Looking at the third picture, I got a question. You didn't run teh cutter between the chuck and the steady to get he appropriate taper on the OD of the barrell? I thought it would be easier to just use a right hand cutter and then flip the barrell over and just indicate it in again?
John

gunsmith_tony
July 02, 2007, 18:57
Are you referring to the short tapered area behind the gas block?
This will be a new barrel for my Israeli HB. Except for leaving it two inches longer, it will be identical to the original. There's only one taper to cut. And it's short enough for me to cut with the compound.

gunsmith_tony
July 02, 2007, 19:12
And now we have 1"-16 threads with adequite clearence on both sides.

http://www.mandmgunsmithing.com/Images/Barrel_tutorial/Barrel_006.jpg

Time to check the fit...
Thats a DCI receiver by the way. Already more than 5,000 rounds through it and a lot more to come.

http://www.mandmgunsmithing.com/Images/Barrel_tutorial/Barrel_007.jpg

And a little air gap between breech face and secondary shoulder.

http://www.mandmgunsmithing.com/Images/Barrel_tutorial/Barrel_008.jpg

Time to make some chips!
Note the follower rest. A necessity for this work.

http://www.mandmgunsmithing.com/Images/Barrel_tutorial/Barrel_009.jpg

mountainman
July 03, 2007, 07:34
I menat the turning down of the entire barrell past the chamber area. I though all you get with a blank is a rod with rifling in it, no contouring. What set up did you use to machine the contour is what I was asking?
John
Looks nice and let this be a lesson to anyone if you wanna make parts buy tools not toys.

AndyC
July 03, 2007, 07:54
Whoa - that is awesome :uhoh:

I know bugger-all about machining, so it's fascinating to follow along. Why do you need the air-gap? To allow for expansion under heat/pressure or for torquing the barrel onto the receiver?

gunhead
July 03, 2007, 10:22
Originally posted by mountainman

Looks nice and let this be a lesson to anyone if you wanna make parts buy tools not toys.

Small precision lathes/machines have thier place.
Every machine was designed with certain goals, Tony's lathe is a nice size for barrel work.
Rich

Radio
July 03, 2007, 11:32
Originally posted by AndyC
Why do you need the air-gap? To allow for expansion under heat/pressure or for torquing the barrel onto the receiver?
Yes, and Yes. Of primary importance is to seat the barrel against the front of the receiver. I should think the heat expansion would be of lesser concern, if a consideration at all. Check all your builds and you'll see a similar gap.

--Radio

gunsmith_tony
July 03, 2007, 22:47
Originally posted by mountainman
I menat the turning down of the entire barrell past the chamber area. I though all you get with a blank is a rod with rifling in it, no contouring. What set up did you use to machine the contour is what I was asking?
John
Looks nice and let this be a lesson to anyone if you wanna make parts buy tools not toys. Here's my basic method in a nut shell...

http://www.mandmgunsmithing.com/Images/Barrel_tutorial/Barrel_steps.jpg

gunsmith_tony
July 03, 2007, 22:50
Originally posted by AndyC
Whoa - that is awesome :uhoh:

I know bugger-all about machining, so it's fascinating to follow along. Why do you need the air-gap? To allow for expansion under heat/pressure or for torquing the barrel onto the receiver? Not a good idea to have the barrel bottom on the secondary shoulder.

gunsmith_tony
July 03, 2007, 22:56
Originally posted by gunhead


Small precision lathes/machines have thier place.
Every machine was designed with certain goals, Tony's lathe is a nice size for barrel work.
Rich Some "hobby" lathes can be used to turn this type of barrel. It's about travel and spindle bore. Even if you don't have enough travel for full-length cuts, it can still be turned "IF" your spindle bore is large enough.
This lathe has a 4" bore. Most of the time I'm using it to machine new pump shafts, bushings, case rings, etc.

gunsmith_tony
July 03, 2007, 23:16
Actually, the trickiest cut to make is the extractor clearence. Pretty much has to be done by hand.
And a few of you may be wondering why I didn't just cut the blank to length right off the bat. Frankly I couldn't decide on the length. Standard is 21". The blank was 26".
I finally decided on 23"...splitting the difference.

Radio
July 04, 2007, 01:07
That's not a barrel blank, that's a friggin' truck axle.

Great report.

--Radio

SIG552
July 04, 2007, 02:08
Would anyone be so kind as to explain what a barrel blank is? Is it a length of steel into which a .30 thread has been cut?

What about the chamber? Has that been cut too?

Go easy on me, I am completely unschooled in metal work

Thanks,

SIG552 :confused:

mountainman
July 04, 2007, 07:50
neat drawing there, so you had no choice but to flip the barrell over after you finished the recvr threads. cause in the picture it shows that area already as being bigger than the rest of the barrell. How did you go about indexing the flats to the gas spring relief cut? Did you use a indexing table/chuck and tailstock to hold the blank and cut the flats? How long did the whole job take you? I got a hobby lathe (sherline to be exact) and in alum I can only rough to about .025 radius DOC, Imagine how long it would take for me to do a job in steel like say a muzzle break. Thats called playing around on little boys toys. Next machine I bought was a full size bridgeport as I learned my lesson.

AndyC
July 04, 2007, 09:49
Originally posted by SIG552
Would anyone be so kind as to explain what a barrel blank is? Is it a length of steel into which a .30 thread has been cut?

What about the chamber? Has that been cut too?

Go easy on me, I am completely unschooled in metal work

Thanks,

SIG552 :confused:
Interesting read here (http://www.border-barrels.com/articles/bmart.htm)

Stg 58
July 04, 2007, 13:49
this is pretty interesting. You seem to be good at computers also:wink:

SIG552
July 04, 2007, 13:59
Andy,

Thanks boet.

SIG552 :fal:

gunsmith_tony
July 04, 2007, 16:26
Originally posted by SIG552
Would anyone be so kind as to explain what a barrel blank is? Is it a length of steel into which a .30 thread has been cut?

What about the chamber? Has that been cut too?

Go easy on me, I am completely unschooled in metal work

Thanks,

SIG552 :confused: Yep. Pretty much a rod with a rifled hole through it.
Chambering is optional. Most barrel makers will short chamber a blank for an additional (usually small) fee.

SIG552
July 04, 2007, 16:51
Thanks Tony! I presume a short chamber is a partially cut chamber?

SIG552

gunsmith_tony
July 04, 2007, 17:07
Originally posted by mountainman
How did you go about indexing the flats to the gas spring relief cut? Did you use a indexing table/chuck and tailstock to hold the blank and cut the flats? How long did the whole job take you? I got a hobby lathe (sherline to be exact) and in alum I can only rough to about .025 radius DOC, Imagine how long it would take for me to do a job in steel like say a muzzle break. Thats called playing around on little boys toys. Next machine I bought was a full size bridgeport as I learned my lesson.
The flats were cut after all the lathe work was done. It's really simple. Screw the barrel into the receiver until it bottoms out. Center punch a mark at about 10:45 relative to the position of the receiver. Walk it over to the mill and vise it with the mark located at top dead center. Using a 1/2" end mill I then cut the flats on either side. Then I used a 3/4" ball endmill to make the clearence cut on top for the gas nut. Then I used a 1/8" ball end mill for the gas reg spring cut. And that was it for the mill work.
How long? Well, thats hard to nail down. An hour here...two hours there. Around 6-hours would be my best guess. Of course that doesn't include actually installing the barrel and reaming to head space. The locking shoulder I used for the original barrel was a .264". So I just head spaced it with that.

gunsmith_tony
July 04, 2007, 17:18
Originally posted by SIG552
Thanks Tony! I presume a short chamber is a partially cut chamber?

SIG552 Correct. There are two types of chambering reamers; roughers and finishers.
Roughing reamers are designed to remove the bulk of the material that would quickly dull a common finish reamer.
Finish reamers are generally intended to remove smaller amounts of material necessary for final head spacing.
Their also quite useful when building FALs. Keeps you from having to have quite so many different sizes of locking shoulders in inventory. And at $25 bucks a pop...thats a pretty good savings.

mountainman
July 04, 2007, 19:23
so after all is said and done you wouldn't be willing to sell one for no less than about $450. I know, nobody really appreciates a machinists work and what goes into making individual parts. My bad, thinking about indicating those flats to make sure they are perfectly 90 degrees from the gas nut and spring slots. I guess it really doesn't matter that much and a square and two vblocks would be sufficient. You really did a good job of making what looks like an impossible job doable. How much was the barrell blank if I may ask?
John

gunsmith_tony
July 04, 2007, 19:41
Not much. About $125

moses
July 05, 2007, 00:53
Tony, cool thread!

I recently made a 260 rem barrel for an FAL from a blank.

When you start from a blank with no chamber it is indeed a time consuming job!

It feels very good though when your finished and assemble and then shoot it and it shoots, works and is accurate!

I actually make a rough cut on the extractor releif on my mill (barrel at 55 degree angle or was it 50?) and then hand file the sides of the cut, it really goes a lot quicker for me than filing the whole cut.

I use an indexing head to hold the barrel to cut the flats and gas nut clearance. I have a large and small one for all the different muzzle devices I make.

I am also thinking about making a light weight shorty gas system 260 rem barrel for my para. (260 rem for those who don't know is basically a 6.5 x 55 swedish mauser but in a necked down 308 case)
I did buy a rougher and finisher reamer for 260 rem because I plan on doing a few.
I knew all my buddy's would want one after they saw mine!

gunsmith_tony
July 05, 2007, 18:07
It feels very good though when your finished and assemble and then shoot it and it shoots, works and is accurate! Quite true.
I actually make a rough cut on the extractor releif on my mill (barrel at 55 degree angle or was it 50?) and then hand file the sides of the cut, it really goes a lot quicker for me than filing the whole cut. I may try that on the next barrel. I have a good indexer, but I need to mount a chuck on it.

gunsmith_tony
July 05, 2007, 18:18
Cutting the short tapered section to the gas block shoulder was done with the compound slide. As it is only about 3.5" long, I figured by the time I assembled the components for the taper attachment and set it up...I'd have it cut. Basically I just cranked it back and fourth over the taper with a dial indicator, adjusting as necessary until the needle was at zero at both ends.

http://www.mandmgunsmithing.com/Images/Barrel_tutorial/Barrel_010.jpg

http://www.mandmgunsmithing.com/Images/Barrel_tutorial/Barrel_011.jpg

Worked out to "around" 2-degrees.

http://www.mandmgunsmithing.com/Images/Barrel_tutorial/Barrel_012.jpg

Two cuts and it was done.

http://www.mandmgunsmithing.com/Images/Barrel_tutorial/Barrel_013.jpg

Potshot
July 06, 2007, 01:53
Tony,
VERY nice thread. Noticed you switched to 3-jaw chuck. Why did you spec 4-jaw for the breech threads? I would have thought an adjustable 3-jaw (for runout) chuck would get it. Also, did you single-point breech threads or use a die? My vote is for die as single point is a PITA. Same for muzzle end.

Oh, and GO VOLS!!!

moses
July 06, 2007, 04:09
I'd bet he single pointed them!
I know Tony, he is alot like me when it comes to smithing and I definitely single point my threads. :bow:

mountainman
July 06, 2007, 11:26
Yeah but that die just floats and cuts in line to whatever it feels like. Single point is true to the center of whatever you got chucked in that lathe. Its also more accurate as you can increase your depth of cut as opposed to try and get rid of it all in one pass like on a die.

gunsmith_tony
July 06, 2007, 17:24
Originally posted by Potshot
Tony,
VERY nice thread. Noticed you switched to 3-jaw chuck. Why did you spec 4-jaw for the breech threads? I would have thought an adjustable 3-jaw (for runout) chuck would get it. Also, did you single-point breech threads or use a die? My vote is for die as single point is a PITA. Same for muzzle end.

Oh, and GO VOLS!!! Any barrel section diameter I consider "critical" I do with a 4-jaw. That way I can dial it in just the way I want it. I didn't care if that short tapered section had two or three thousandths run out, so I used the three-jaw.
Moses has me dead to rights...I never use dies on barrel threads. I lathe cut all my threads with a 4-jaw. As for it being a PITA, thats kinda relative. I cut threads regularly. Breech threads were cut to full depth in three passes and two passes at the muzzle.
Lathe cut threads are better than die cut...in my view anyway. It enables you to thread perfectly true with the bore and/or chamber.
The brake I made for the original barrel worked very well. Felt recoil was about like a .223
One reason for that was the only .003" clearence (.006" overall) around the projectile at the exit hole. Hard to get that kind of accuracy with a die.

gunsmith_tony
July 06, 2007, 17:28
Originally posted by moses
I definitely single point my threads. :bow: I had my suspicions about that. You don't get as good as you are by taking a lot of shortcuts.

gunsmith_tony
July 06, 2007, 17:32
Originally posted by mountainman
Yeah but that die just floats and cuts in line to whatever it feels like. Single point is true to the center of whatever you got chucked in that lathe. Its also more accurate as you can increase your depth of cut as opposed to try and get rid of it all in one pass like on a die. Yeah...'bout the only thing I use dies for is chasing existing threads.

gunsmith_tony
July 06, 2007, 17:37
I'll be test firing this Sunday. Hopefully, the .096" port will be large enough. We'll see. :fal:

Potshot
July 06, 2007, 23:05
May allah bless you with groups that match your gas port size....

gunsmith_tony
July 07, 2007, 15:49
Originally posted by mountainman
I know, nobody really appreciates a machinists work and what goes into making individual parts.Thats generally true. I'm also the "Machine Shop Services" of On-Site Mechanical. Last months project came from a neighboring business in our little strip. A guy needed a radiator cap for an antique car he is in the process of restoring. Took me around four hours to make it. I ended up getting $200 for it. Not too bad.
I know it's off-topic, but what the hell.

http://www.mandmgunsmithing.com/Images/Rad-cap-01.jpg
http://www.mandmgunsmithing.com/Images/Rad-cap-02.jpg
http://www.mandmgunsmithing.com/Images/Rad-cap-03.jpg

gunsmith_tony
July 08, 2007, 14:08
Well here it is. The (un-Parkerized) finished product.

http://www.mandmgunsmithing.com/Images/Barrel_tutorial/Barrel_015.jpg

The barrel turned out very nice. I decided to use one of my custom brakes instead of the original. I never used the bipod anyway.

http://www.mandmgunsmithing.com/Images/Barrel_tutorial/Barrel_016.jpg

R1 butt, Imbel carry handle, oversize joint pin, stripper top cover w/red dot...

http://www.mandmgunsmithing.com/Images/Barrel_tutorial/Barrel_017.jpg

And best of all...MUCH tighter grouping compared to what I was getting from the original barrel. Thats 10-rounds with a red dot on a bench from 75-yards.
I am VERY pleased!

http://www.mandmgunsmithing.com/Images/Barrel_tutorial/Barrel_014.jpg

I did end up opening the port to .104". Luckily, I thought to bring the cordless drill and a handful of drills with me.
And I figured while I was doing this rifle renovation I'd do something about that irritating .020" air gap I had between the rear of the upper and the recoil plate.
Before installing the barrel I stripped the upper and lower. Fixtured them together the way I wanted them to interface, located the spindle over the joint pin hole and reamed it .035" larger. Then machined and hardened two oversize joint pins to fit the new hole. One to use and one spare.

This is great. It's like having a whole new rifle. Perhaps a FAL Match winner even. :biggrin:

Conju
July 11, 2007, 12:22
VERY cool! Did you have any more pics of the manufacturing process?

gunsmith_tony
July 11, 2007, 21:27
Well...actually I did. Twelve to be exact. But my memory card went FUBAR on me. I don't have a clue why. Never happened before. Images were there one day, and gone the next. I'm pretty tech-savy...usually I can figure these things out. Even so, this one has me stumped. New card works fine though. We'll see.
Anyway, this thread is far from over. I have another blank on order that has G1 barrel written all over it. So...more to come. :fal:

moses
July 13, 2007, 00:37
You gonna make it with the G1 lug on the end?
If so that should be real fun!

AndyC
July 13, 2007, 15:13
Images might have been accidentally deleted - try this (http://www.snapfiles.com/get/mjmphotorecovery.html), it's free.

gunsmith_tony
July 13, 2007, 19:03
Originally posted by moses
You gonna make it with the G1 lug on the end?
If so that should be real fun! Yep. Already worked out how I'm going to do it.

moses
July 14, 2007, 03:41
OK, I give....... you got a rotary vice?

Lets hear your plan on that lug!
:bow:

mp
July 14, 2007, 09:11
Nice write up.
very interesting

gunsmith_tony
July 14, 2007, 18:30
Originally posted by moses
...you got a rotary vice?
Not far from it. A rotary table mounted vertically and a 8" 3-jaw chuck mounted to that.

moses
July 15, 2007, 22:27
Doh! yeah that's what I meant rotary table.

You can do a lot of cool stuff with that set up!

I need one!

mountainman
July 16, 2007, 18:18
I was thinking about getting a 6" chuck for my 8" table. Do you have an 8" chuck on an 8" table and if so how are you mounted on there? I was thinking of making an 8" plate with holes wherethe T bolts goe and have enough oversize in the table mounting holes so I can give the chuck a few taps till the master ( 1/2" pin gauge) in the chuck gives .0005 TIR on the test indicator.

TFA303
July 20, 2007, 15:17
Great work. I "owned" the machine shop on my last ship, and I loved to just hang out and watch my guys work. It really is a pleasure to see art and science merge like that.

mountainman
December 13, 2010, 07:07
anyway we can get the photos back. BTW, Tony where do we go for the barrell blanks short chambered and all?

Oklahoma Joe
December 15, 2010, 03:32
Originally posted by mountainman
anyway we can get the photos back. BTW, Tony where do we go for the barrell blanks short chambered and all?

+1 on getting the pictures back.

DYNOMIKE
December 15, 2010, 09:00
Originally posted by mountainman
anyway we can get the photos back. BTW, Tony where do we go for the barrell blanks short chambered and all?

Tony used to be a regular poster here and did a lot of smith work but has not been around for quite some time now.. Without contacting him getting the PICS back is gonna be tough as they were prolly loaded using a hosting service?

Oklahoma Joe
December 15, 2010, 09:13
Originally posted by DYNOMIKE


Tony used to be a regular poster here and did a lot of smith work but has not been around for quite some time now.. Without contacting him getting the PICS back is gonna be tough as they were prolly loaded using a hosting service?

Yah there used to be a lot of guys on here that are not around any more!:rolleyes: