To the OP,
Here is a perspective from a total rookie who is still in the crawl phase in this barreling and machining world. When I retired at age 59 I was happy and content shooting in competition all year round burning up 2 barrels a year, until one day due to some incidents, finished barrels we use are hard come by, 6 months and longer. That was when I decided to go ahead and purchase the machines and learn how to do my own barrels.
October of 2014, I lucked out and found a Bridgeport and a 12x36 Taiwanese lathe that are both accessorized very well as a package. But, as others have said, tooling up used equipment will cost you more than the machine acquisition. A shooter friend from Memphis, a machinist by trade guided me through the initial machining operations and practices, there are no classes I could take in our area, long distance learning from my buddy was all I could do to get started. We started with the inspection, alignment of the machines. I even had to re-align the headstock on the lathe. The first tramming job on the mill was whole day affair. Learned about rigidity, rigidity in everything.
A shooter friend from Louiisana who does his own barrels gave me a shopping list of what other tooling I needed, some I bought new, others I set an alert on Craigslist from Dallas to Houston. I found a few good deals from the latter. For cutting bits I looked for them on eBay
When I started learning about feed, speed, depth of cuts relative to facing, turning, and parting, it was like a practice in patience. I learned that there are rules and there are no rules as to what works and does not, way too many variables. You just have to soldier on. My first dialing job with a 4J took me hours. I was told and read rookies must learn how to grind their cutting bits, I by-passed that, I went straight to indexable cutting tools so I can dive right into cutting metal. It may be the wrong way, that's what I did and still continued to use.
Machine operation training. I started with unkown rusted steel, which provided some kind of revelation and surprises on how different materials cut to achieve good finish. Once I got the basic operation and familiarized with the machinie controls, my next training exercises were to actually cut materials to specific dimensions, I made small brass hammers, and refrigerator magnets for the ladies of the family. These were the very first useable products I rolled out.
Early last year, was when I started to extend the training on barrels, from my years of shooting I accumulated shot out SS AR barrels, these and others donated by friends in high power I have ample stock of good material to train on, Friends have been with me and helping me from the start. When I started chambering training exercises, I seeked the advise of Butch Lambert, who was really very patient with this kid. He explained how his practices were and I followed them to the letter. With my supply of shot out barrels, I was able to cut the tenon, turn, thread, drill/bore, finish and cut off the tenon again and do it all over. I lost count on how many dummy chambering I did before I did my first barrel, a $60 Green Mountain barrel
It was not all that rosey along this journey, had to repair the old lathe a few times. On the first expensive barrel I did for me, Shilen Select Match, I broke and stuck a carbide bit drilling the gas port. When I did the fireforming barrel for my brother's 30 BR, I cut the tenon and threaded it, Butch's fixture would not screw in, cut the tenon again, threaded it again, still the fixture would not screw in. Then I look at the Borden print for the action one more time, I discovered I could not read, it is 18 TPI and whereas I cut the thread at 16, twice. I am sure others have not made that mistake.
OP, get your machines and jump in there with both eyes and ears wide open, and don't be shy to ask others for help.
Sorry for the long winded response.
