I have turned 2 Border 1.350ish blanks to Remington Varmint contour and 2 Krieger and a Shilen 1.250 blanks to .9ish muzzle diameter with a straight taper. I offset the tailstock on my Craftsman/Atlas lathe and use a steady and keep moving it and only 6" at most per set up. A lot of darn work and messing around but I bought the blanks reasonable and have nothing but time on my hands since I cannot work anymore.
Using a manual lathe if one were attempting to make some machine time and pay himself a decent wage it would be a bargain to have it ordered as you want or pay shipping and have manufacturer recontour.
Most say you shouldn't recontour a button rifled or hammer forged blank because of chance of internal dimension changes, only cut rifled are a fairly safe bet. Probably more true than not but I bought a 40-XB 22 rimfire stripped barreled receiver off Gunbroker last summer for a more than fair price. Seller listed it as having substantial barrel rust so figured I was still good with the stripped receiver at what I paid. When it arrived it had pretty heavy surface rust that had lightly pitted and discolored metal underneath. Thought I would/could take a .010 or so off diameter as they are straight taper but the 28" barrel had about .030 bow in the middle so that was out. Soooo....I did the other "DO NOT DO with a rimfire" which was remove it from receiver (the rimfires are just unreal tight I have discovered) and whacked it to 22" and change. Set it up on centers and figured taper I wanted for close to a Remington Sporter contour and started cutting! Offset tailstock and cut taper I wanted from muzzle back 16". Then figured taper from there to where it would leave barrel date codes and cut that in steps and finished with a file and emery.
I had thrown parts together and checked it at the range before all this with Mini Mags, Green Tag, 711 and some Wolf Target. At 50yds I had some groups around .4 and overall it shot pretty decent considering the crown was pitted and looked like it had 15yrs of carpet burn but doubt it was ever carried that way.lol Anyhoo, after all my messing around and cut and new crown @ 22" I took it back to the range in another pillar bedded stock I had but not bedded to that barreled action. Best 5 rd group @ 50yds was IIRC .3ish and most with Mini Mag, Wolf and 711 were .5 at most. So for a pdog plinker out the truck window etc it shoots way better than necessary despite recontouring a non cut rifled blank and not slugging a rimfire barrel and cutting at a tight spot. So the barrel shot as good or better than before I messed with it but think any actual improvement in accuracy was because of the new crown!
Moral of the story, anything MIGHT work in your favor or satisfactory but you will never know what result you get until the chubby lady has finished her solo!!
I sure wouldn't do it for anyone else and wouldn't bet a dime on the end result, I work cheap for me though. lol
Respectfully,
Dennis