Is there enought meat on a mauser stepped barrel to do a transition like these?

I haven't measured and done the calcs, but I am working on a rifle where I am installing a new stepped barrel, and my gut level felling is that there is not nearly enough difference to cut the octagons. If that works, the wedding band will easily fit, but octagons take quite a bit of delta. If, sy the section downstream of the octagon is to be 0.8", then the octogen needs to be near 0.9" across the flats, which would require something close to 1" to cut.

I'm think of having this done on a round to round transition. No Octagon.

Rich

It would be possible, so long as you do not want the band to be larger than the portion of the barrel from which you are stepping down.

It is really just a question of making the step down, then going back to the barrel portions just before the steps, and cutting the relief grooves to form the back sides of the "wedding bands".

If it was me, I'd make a special cutting tool with the proper radius, and align the front of the tool with the front edges of the "rings". Then by using the crossfeed to feed the cutting tool at a true 90-degrees to the axis of the bore, I think it might work out rather well. I'd try it first on a trial piece of round stock, though, not on my barrel.