Back in my earlier years, probably when my dad moved us to Houston in 1965, the company he work for had several special machine tools that were built from surplus WWII ordnance equipment. They were old gun barrel drilling machines built by LeBlond Machine tool. Of course, they were stripped of any tooling capable of being used for gun barrel manufacturing. They took these machines and "soup them up" with higher spindle speeds, more horse power, BTA style tooling for trepanning deep holes in steel bars. These machine tools were referred to as "4GSR", for their size. LeBlond built these machines in sizes from a No. 1 all the way up to a No. 7 machine. The most popular was the No. 4 machine. If you contacted LeBlond about these machines, they would tell you that they have no recollection of ever building these machines!
Anyways, moving forward to around 1977, I went to work part time, while in college, at a place in Houston that had a couple of these machines set up trepanning holes in steel bars. In three years I worked there I help rebuild/retrofit many of these old gun boring lathes. Again, the old LeBlond one's were the most popular to retrofit into trepanning machines. As I said, 4GSR, the "4" represents the machine size, BTW- these machines were built in lengths up over 100 feet long. The "G" represented gun drilling, The "S" indicated skiving, and the "R" indicated rifling, which some of the machines were originally equipped with the gear to "rifle" the gun barrels. That's where my handle originated from. Ken