I had a 600 pound Rockwell 21-100 mill and replaced it with a 2000 pound Bridgeport series II.
The old mill would have been just as good for gunsmithing projects if I had:
1) installed DRO
2) installed auto feed
3) rebuilt to get the backlash out of the X axis.
You only need to adjust the gib to take the backlash out of the X or Y axis,....5 minute job. Basically, it involved turning a screw with a screwdriver.
Also, the lead screw is affixed to the table of the milling machine with a split nut,...usually bronze. If the backlash is coming from wear on the split nut you only need to spread the split nut via a tapered screw which is threaded into the split in order to spread the nut which tightens the relationship between the nut and the lead screw.
Milling machine tables are designed to be adjusted. They'll loosen up over time and will need to be tightened up. It's not a big job.
