Better than no steady at all
I guess it would freak the engineers out if I also admitted that, at the time, I used a 3 jaw chuck to grip the breech block and shimmed 2 of the jaws out with a mix of shim steel an paper?...
As I side note, I have never charged for my hamfisted bodges, done them just for the fun of doing it and having a go.
I don't make parts for NASA so meh...