I'm not Brad, but yes Brian..in order for a given program to work part to part - it would in fact require the same contour rib to rib.

Programs can be adjusted fairly easily to accommodate a different contour.

If I was matting new ribs and had several barrels with variable (yet close) contours, I'd be inclined to run a cut along the entire rib surface followed by the matting cycle.

The pre-cut would ensure perfect depth of the matting cuts part to part.

I must have just been speaking with the wrong people then. I have been in communication with a number of machine shops over the last couple years or about the possibility of CNC matting ribs. They all either have no clue as to how to do it, or are scared off by the concave aspect of it. Obvously it can be done. The repros were cnc matted (straight, not tapered) and i am sure Galazan is doing the few new parkers built the same way. If i am not mistaken, anything Brad's shop has is from the failed Simmons Parker barrel making project. And my last discussions about matting a concave rib wih simmons turned the same hesitant answer.

Reprofiling original ribs may well be a good option, especially since the fact that they are being re-matted requires removing worn or pitted matting to start with. But some ribs may not tolerate re-profiling. Likely the best way to be able to consistently rework original barrels is to replace the ribs with new and then profile and matte.

The Parker matting machines at the factory did not profile the ribs. This was either a separate operation (as outlined in American machinist), or yhe ribs were pre-profiled. As evidenced by the box of original parker ribs that i have here in my shop. Some are flat and some are concave. Maybe they still ran a profiling operation on all ribs once installed on barrels regardless of the beginning state. But, either way, there was a large variation in contours possible on barrel sets. The original mechanical machines likely may have been adaptable to a changing surface as it ran.
I do know one of the gunsmiths that worked at the Lefever Arms operation and he ran the Parker machine they had a lot. He still owns guns of his own that he matted with the machine. In our discussions of the operation of the machine, this is one factor of it that we did not discuss. i will have to ask him.

I appreciate the additional info Brian.

If I had to guess..and yes, that's all it is..I would have guessed that the matting was rolled just like barrel stamping..I could be wrong <or> there simply was no firm fixed method shop to shop.

Another thing I will definitely affirm & can proclaim w/a fair degree of certainty (w/out benefit of diligence on the subject), the contour would have been machined prior to matting; either with conventional cutting tools (ball mills), grinding op, or using a planer...my best guess while considering the age of the process would be the utilization of a planer to cut the contour & possibly finished by grinding or handwork to apply the proper finish.

The fact that you run into a bit of hemming & hawing is of no surprise to me whatsoever for many reasons. The cost benefit is a difficult element to overcome due to the degree of setup..especially one that would accommodate any given set of barrels that happen to walk through the door on any given day.

Plus..and speaking to Mr. Murphy's point..a CNC mill with a working envelope required to do the machine work properly is actually quite large.

I own CNC equipment & I could do it in my shop but it would have to be done on a Bridgeport..even that would be pushing the envelope as well due to the fixturing which robs a goodly amount of machining space.

I can think of several ways to skin that cat and the most likely scenario would involve a dividing head or a rotary table to ensure the matting cuts are perfectly perpendicular to the rib surface about the contour..it wouldn't be right nor look right if this was not the method employed using conventional cutting tools. THEN you have the matter of making sure your tools are and remain very sharp so as to not throw up a nightmare of a burr to contend with following machining.

Going back to CNC..I myself have not done any significant degree of engraving by machine.

I can visualize a heavily spring loaded engraving tool that would negate the necessity to rotate the rib about its contour in an engraving operation..I may be talking right out of my you know what w/that though..seems feasible.

I'd very much like to hear from any other machining professionals who may have experience w/engraving.

I'd also like to add one last tidbit..despite popular belief..CNC is not some magic machine that you just throw a slab of metal into and push a button..that's quite an oversimplification in fact.

While you'll be hard pressed to find somebody whom appreciates hand work & fine fitting more than me - I'd also state that it may be a fairly quick rush to judgement while considering the use of CNC technology vs conventional machining & hand work.

In the proper hands, CNC is just a tool like anything else.

Make no bones about it... the original rib matting at Parker was NOT rolled. It was CUT.

It was done with a single cutter head that was dragged through the metal. Dispacing it more than cutting actually. It was done one line at a time. Then the machine would re-index for the next line.

The barrels fed on one axis while at the same time the cutter head moved back and forth on the opposing axis thus creating the wavy line. The amplitude and latitude of the line changed as it went down the length of the barrel. This caused the lines to naturally converge on a taper. This was done utilizing a special cam in the machine.

The barrels sat on a table that was a "U" type shape and could be trunioned back and forth for concave ribs or locked in the middle for flat ribs.

The cutter was lifted and restarted in order to leave the blank for the makers mark which was rolled on or hand engraved in some instances.

Welp..there you go..sounds like there were no rotating tools involved whatsoever.

What you describe sounds like a modified planer using a single point swaging tool..interesting..have a link to photos/video?

I'd like to see that.

This somewhat jives w/my guess that it was rolled in the sense that the material was displaced.

All that said..you're now describing equipment that is not widely used today as compared to yesteryear.

Any rib can be recut with the right set-up. We have always done it prior to profiling. To run ribs, it requires a dedicated machine and operator.
We are planning runs up to 34". hopefully we can get it set up soon, currently we are focused on our backboring operation.

Brad

Ah, that's what I want to hear " focused on our backboring operation ". It's been awhile " buddy ".

If someone here wins the lottery it looks like you would have some potential employees with the skill necessary to start up the Parker operation again.

I can finish your project, is new barrel setting up at the same point of impact?