factory barrel contouring

H

Hal

New member
How do the custom barrel manufactures contour and polish the exterior of their barrels.

I had a #4 contour barrel in the lathe, between centers and was going to turn the shank down from 1.250 to 1.150 to match the factory contour.

I put a dial indicator on the shank just to see the run out, it measured .004 total run out between centers.
I than measured the diameter and it measured 1.2495 in several places.

I was wonder where the run out came from?
Do some barrel makers contour the barrel blanks before drilling them?


Hal
 
I just got back from Douglas barrel today visiting Tim Gardner and his gang. They are one of the few that offer the service of exactly duplicating your factory barrel contour. He has a nice Monarch tracer lathe that used your old barrel as a template which gives you an exact copy. So if you have a nice custom stock but just need a new barrel. of any caliber or chambering, that is the place to go.

Tim and Stanley Taylor showed us a lot of barrel making tricks.

As to runout of ID vs OD some gunsmiths and some barrel makers see that as important and some don't. Functionally it makes no difference, IMO.
 
And another thing.........

I like and use Douglas barrels on many of the projects my customers send me. I should note that the contour duplication service that Douglas offers ($50) is great to have, but.... The barrel that I get back is about 0.010 larger in diameter at every point than the original. Don't expect to get by without some polishing.

Bill Jacobs
 
Clemson said:
I like and use Douglas barrels on many of the projects my customers send me. I should note that the contour duplication service that Douglas offers ($50) is great to have, but.... The barrel that I get back is about 0.010 larger in diameter at every point than the original. Don't expect to get by without some polishing.

Bill Jacobs
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Just tell Tim or Stanley what you want. They leave them oversize to allow for polishing. If you want them to polish a barrel, that costs you extra. Their time is valuable too.
 
10 thou, holey cow, that's a lot of polishing! ;) My bet is that the ten thou is safety margin for the pantographing setup.....
 
Nope, the 0.010 is to allow for the 250 RMS finish the CNC is programed to leave.
If the OD were finished to, say, 63 RMS the cost to profile would about triple.

So, now you would be up to about $150 for Douglases service. Then add polishing?? Probably another $50 or so.

Ain't no free lunches in the machine shop business unless the shop goes broke, then the free lunch is at the local soup kitchen!!
 
I'm certainly not complaining about the duplication service. As I stated, I USE IT. I just don't want folks to think that the barreled action will drop right back into the original stock. Not going to happen. It takes some time to get it back into that nice hunting stock where Great Uncle Pete so lovingly inletted it originally.

Jerry, I agree that they are super-accomodating people. One thing that I wish they would do is update the price list on their website. Just before Christmas last year I ordered a half-dozen odd barrels for my barrel fitting class. I had to go back to the students for more money because the prices had changed. Among college students, that was about as popular as a flatus in a diving bell!

Bill Jacobs, aka "Clemson"
 
Clemson said:
Jerry, I agree that they are super-accomodating people. One thing that I wish they would do is update the price list on their website. Just before Christmas last year I ordered a half-dozen odd barrels for my barrel fitting class. I had to go back to the students for more money because the prices had changed. Among college students, that was about as popular as a flatus in a diving bell!

Bill Jacobs, aka "Clemson"
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Bill, their IT department is on vacation this year, I think. As with any of this type ordering, if price is an issue, I call first.

I taught college in the evenings for a few years, tell the students you will give them a D if they complain!!
 
Make it into a "teaching moment"..........say as how "out in the real world when stuff like this happens you get to eat it..on a customer's rifle."
 
250 RMS finish

JerrySharrett said:
Nope, the 0.010 is to allow for the 250 RMS finish the CNC is programed to leave. /QUOTE]

To clean up the 250 RMS finish...
A file is a good place to start then some 120grit then 180grit. This will get you to where you would have started if you'd paid for the extra finish option. Now go to 240 grit at about 1000 to 1400 rpm and see how long it should've taken to make it look right.

I've done it both ways several times, tell Stan you want the sanded finish when you order your barrel it's well worth the extra cost.
Click to expand...
 
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