SO HERE IS HOW I ACCOMPLISH THE BARREL TURING DELIMIA...
Being old and a retired machinist with guns as a hobby. I always do the task myself...that way it gets done correctly in a timely manner..
First go back in time when I was a young man.
P.O. Ackley was the man... tapering barrels in small gunsmithing lathes, was actually accomplished, as many know...there were no CNC machines, no DRO, no computer. I learned that trade ...then back to college for CNC programming as times change.
This actually works for me with nice finishes..
But I won't do it and I won't recommend it for competition barrels. Because the barrel steel may not be stress relieved...then it should be re-straightrned after each cut. I have done a lot of straightening but not rifle barrels. It requires fixtures and a press, with dial indicators. Not for the average guy.
So grind the high-speed tool according to PO Ackley's design...it works!... in smaller standard lathes. Books From Ackley and Gunsmithing Kinks volume 4 pages 161- 164.
Set up between centers with a driving dog... then offset tailstock the appropriate amount.
Use heavy dark cutting oil, with all the caustic ingredients, cancer causing agents warnings of skin, eye, respiratory flammable warnings ...seriously good stuff, used it for years, and it does irritate.
Those old take off barrels are used as a guide to adjust feeds, deptht of cut and finish...use the old barrel first of the same material. My experience was with the chrome moly in actual barrel turning. And harder to get good finishes.
About 200 to 225 RPM with .005" per revolution is where to start ...on your old scrap take-off barrel of the same material. So you can adjust feed, speed & depth of cut, while adding the dark heavy tapping/ cutting oil. Regrind tool if necessary, keep it sharp. The finish will be nice and chatter free 5 or 6 passes depending on the variables and how much taper reduction is needed...but you have to do a little experimenting with "your lathe" and its rigidity or lack there of...no modern attachments, or duplicators, needed or CNC ...But it's a lot easier with the modern tooling applied. And why order my barrels with the already desired profile. And when you indicate a new barrel for threading for a muzzle device off its bore, and notice the OD is not true with the bore, very common and very telling...no matter who the manufacturer is...they profiled this one first, before rifling. Cause it's impossible to turn a the barrel between centers and have the bore to OD run out .010", it should be .0002" max, right next to the lathe live center...or 50 millionths inch max TIR in a CNC live center.
