Duplicating a pistol barrel

[A.D.D.]

Good day,
Im looking to make a new barrel for one of my personal firearms.. a MAB model D… my original barrel is damaged at the muzzle… I found a blank that will be suitable.. I have no problems turning the barrel to the dimensions and reaming the chamber as needed.. What is throwing me off is the off-set "lobe" of the barrel locking lugs. They protrude about .060" below the breech of the barrel, and I have NO idea how to turn or mill this section.
If I am allowed I would post a single pic of the "lobe" I'm referring to. If this isn't possible Illl try to attach a link to photo bucket so you may take a look.
Any suggestions or links to previous post or videos would be greatly appricieated,
Shawn.

 

[xalky]

Good day,
Im looking to make a new barrel for one of my personal firearms.. a MAB model D… my original barrel is damaged at the muzzle… I found a blank that will be suitable.. I have no problems turning the barrel to the dimensions and reaming the chamber as needed.. What is throwing me off is the off-set "lobe" of the barrel locking lugs. They protrude about .060" below the breech of the barrel, and I have NO idea how to turn or mill this section.
If I am allowed I would post a single pic of the "lobe" I'm referring to. If this isn't possible Illl try to attach a link to photo bucket so you may take a look.
Any suggestions or links to previous post or videos would be greatly appricieated,
Shawn.

I'm not sure if theres a minimum post count required for uploading pictures direct to the site. I always use my photobucket to post pics, I find it easier. If you copy and paste the IMG code, from your photobucket picture page, into your post, the picture will show up directly in the post.

 

[A.D.D.]

Trying a copy of the link to photo bucket. ok.. Here is a pic of the "lobe" I need to attempt to duplicate. HOW would I do this?

 

[Ray C]

Does that lobe have a uniform radius or, is it like a cam?

Anyhow, it could be turned in a lathe using a 4 jaw chuck in an offset position or, it could be setup in V-clamps on a rotary table and done on a mill.


EDIT: If that's a finished barrel and it's hardened, that will be a little hard (but not impossible) to do either way. Barrels are usually in the 50C Rockwell range. I'd suggest practicing on a piece of practice stock first...

Ray

 

[xalky]

Trying a copy of the link to photo bucket. ok.. Here is a pic of the "lobe" I need to attempt to duplicate. HOW would I do this?

If your barrel blank OD is at least as big as the lobes plus an imaginary lobe on the opposite side you can turn the lobes and grooves on the lathe and the machine out the part of the lobe you don't want. Does that make sense?

 

[Ray C]

Oops... Never mind what I said about the lathe. It's a no-go on the lathe. This is best done on a rotary table on the mill.


Ray

Does that lobe have a uniform radius or, is it like a cam?

Anyhow, it could be turned in a lathe using a 4 jaw chuck in an offset position or, it could be setup in V-clamps on a rotary table and done on a mill.


EDIT: If that's a finished barrel and it's hardened, that will be a little hard (but not impossible) to do either way. Barrels are usually in the 50C Rockwell range. I'd suggest practicing on a piece of practice stock first...

Ray

 

[ranch23]

Barrels are available for some of those guns. GunParts.

 

[The_Crusher]

Simple enough to do on a lathe with a 4 jaw chuck by off setting it to get the proper radius and turnin that radius on that portion first and the you would have to center it up and use a ground to width parting tool to make the grooves. At that point turn the rest of the OD of the barrel and then you could finish the rest of the remaining barrel with a whirlygig on a surface grinder with stops set and od grind finish the od of the barrel too.

 

[A.D.D.]

Does that lobe have a uniform radius or, is it like a cam?

Anyhow, it could be turned in a lathe using a 4 jaw chuck in an offset position or, it could be setup in V-clamps on a rotary table and done on a mill.


EDIT: If that's a finished barrel and it's hardened, that will be a little hard (but not impossible) to do either way. Barrels are usually in the 50C Rockwell range. I'd suggest practicing on a piece of practice stock first...

Ray

Ray.. its a uniform radius. not egg shaped like a cam shaft.
ist like the lugs and grooves were turned first. then the excess not needed for the locking lugs was milled.. then the barrel turned to size.
And yes .. the available blanks will have enough material to make a full corcumferential lugs.. and then take off what it is not needed.
I found blanks at gun parts corp… the N.O.S. barrels they have are indexed with a protrusion of metal.. my barrel is not indexed (its that old!) And besides.. I can get 3 blanks for what one N.O.S. barrel cost!
Thanks for the input guys,
Shawn

 

[rangerman]

If the lug's outside profile/radius is concentric with the chamber or the bore center axis and larger than the radius of the barrel's outer radius it's possible to machine part of it with a lathe,
However, clamping it to a rotary table and milling the outside contour with a milling machine would be the more practical approach for a complete machining process on that barrel's irregular section.