For those of you who have customs with octagon barrels with integral ribs or 1/4 ribs, what treatment do you give the top of the rib?

I particularly love the wavy pattern on older german sporters. Does anyone do anything similar these days? How was it done? Roll form? By hand?

Roll die machine.

Roger,

I wondered if it was not some form of roll die. Anyone do anything similar these days?

Maybe it is time to talk to grandpa about making one up.

I know there are quite a few with roll die machines, but I'm not sure if the machine is big enough to roll an entire barrel. You might talk to Doug Turnbull. I know he rolls factory type lettering onto barrels. He might, or at least, might know someone who does.

Good luck

Roger

A rib matting machine is what you need.

The guy that used to work on all the 21s had one... Keith something???

On a piece of scrap, try a "rat tail" or round file..roll the file perpendicular to the bore like a rolling pin. A not unpleasing pattern will result

Duane,

Thank you for the tip! I will give it a shot tomorrow.

If you want something a little more consistent looking, I would grab a lathe knurling tool, and try to set up some sort of pressure/rolling system that puts quite a bit of pressure on the wheel and rolls straight. The type of knurling wheel would determine the pattern. Two trips though in opposite directions with a diagonal wheel should give a diamond checkered pattern.

When I was in gunsmithing school I made one up from a rat tail file. I cut a section from a large one and ground the ends to fit a ball bearing on each end then put it in a 'Y' shaped handle which I used in a vertical mill. I only did pistol ribs but it made excellant patterns and I still have it somewhere around. That means I've used it off and on for over 50 years. The bearings were used ones from the auto shop so the investment was only labor and the file.

I would like to see that, anyway to get a pic?
Don

I'll look for it and if I can find it I will post a pic. Been years since I even thought about it. I do remember the ends of the file for the bearings were ground using an old tool post grinder setup with the file held in a collet. Don't remember what the bearings were except they were rather small ball bearings with no seals and I would have to flush them out everytime I used it. Used it for a lot of 1911 ribs which were popular back in the 50's.

couldn't you just program a "wavy pattern" into a cnc milling machine and run it through?

I could if I had a 3 axis CNC, or if the top rib was flat.

I had considered that... but making a tool was cheaper than buying a 3-axis

I love my Simson 9.3X62 - Octagon to round barrel. I wish I could get such barrels done at an affordable price - I would then get a 404 Jeffery right away.